Name: Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe
Prep time: 15 min
Cook time: 1 h 30 min
Total time: 1 h 45 min
Cuisine: American
Ingredients: 3 tablespoons whole-grain mustard; 1 tablespoon extra-virgin olive oil; 1 tablespoon apple cider vinegar; 2 teaspoons brown sugar; 2 cloves garlic, minced; 1 (4-to 5-pound) whole chicken; 1 tablespoon plus 1 teaspoon kosher salt; ¼ teaspoon freshly cracked black pepper, plus more for serving; 3 large leeks, trimmed and thinly sliced (about 3 cups); 4 cloves garlic, thinly sliced; 2 lemons, thinly sliced; 1 pound smallish new potatoes or petite gold potatoes; 2 tablespoons extra-virgin olive oil (divided, 1 tbsp for marinade, 1 tbsp for leeks, 1 tbsp for potatoes); 1 cup white wine; 1 tablespoon chopped fresh tarragon, plus more for serving; 4 tablespoons salted butter, cold

Jump to Recipe· 4.9 from 145 reviews

If you’re craving a comforting yet elegant meal that feels like a warm hug, then this Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe is absolutely going to become your new favorite. I love this recipe because it’s a complete dinner all in one pan – juicy, tender chicken, crispy golden potatoes, and sweet, mellow leeks – all infused with a tangy tarragon mustard sauce that brings everything together beautifully. You’ll find that the flavors marry perfectly and it’s surprisingly easy to make, which makes it a total winner for weeknight dinners or weekend feasts.

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Why You’ll Love This Recipe

One-Pan Wonder: Everything cooks together, making cleanup a breeze and flavors develop harmoniously.
Perfectly Balanced Flavors: The tangy mustard and fresh tarragon lift the rich roasted chicken and earthy potatoes beautifully.
Family Favorite: I discovered this trick when I was looking for a dinner that impresses but doesn’t require turning on every burner.
Comforting and Elegant: Whether it’s a casual dinner or a special occasion, this dish always delights.

The image shows a white plate filled with six cooked chicken pieces that are golden brown with crispy skin and some herbs on top. Under the chicken, there are small round potatoes and sliced light yellow onions spread evenly, mixed with green herbs. The plate is placed on a green and white striped cloth on a white marbled surface. On the right side of the plate, there is a large knife and a fork with wooden handles resting on the surface. The colors of the food are warm tones of golden brown, yellow, light green, and beige. photo taken with an iphone --ar 2:3 --v 7 - Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard, Roast Chicken with Potatoes and Tarragon Mustard, Easy Roast Chicken Dinner, One-Pan Roast Chicken, Comforting Roast Chicken Meal

Ingredients You’ll Need

These ingredients are simple and easy to find, yet they work together to create layers of flavor that make this dish extra special. Pro tip: choosing baby new potatoes and fresh tarragon really elevates it, so try to grab the freshest you can.

Flat lay of a whole raw chicken with smooth skin and clean surface, a small pile of small new potatoes with golden skin, a few fresh leeks thinly sliced showing white and pale green rings, a pair of bright yellow lemon halves thinly sliced, several whole uncracked brown garlic cloves alongside a few peeled minced garlic cloves in a small white bowl, a small white bowl filled with whole-grain mustard showing visible mustard seeds, a small white bowl of golden extra-virgin olive oil, a small white bowl with clear apple cider vinegar, a small white bowl containing fine light brown granulated sugar, a small white bowl with coarse kosher salt, a small white bowl with freshly cracked black pepper, a small bunch of fresh green tarragon sprigs, and a few small cubes of cold salted butter arranged neatly in a simple white ceramic dish—all ingredients arranged symmetrically and balanced, placed on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p awthu7i m7354615311229779997 - Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard, Roast Chicken with Potatoes and Tarragon Mustard, Easy Roast Chicken Dinner, One-Pan Roast Chicken, Comforting Roast Chicken Meal

Whole-grain mustard: Gives a lovely tang and texture to the chicken rub; look for one with visible mustard seeds for extra punch.
Extra-virgin olive oil: Use high quality because it adds richness and helps with roasting.
Apple cider vinegar: Adds a subtle brightness that balances the richness of the chicken and butter.
Brown sugar: Helps caramelize the mustard glaze and add a touch of sweetness.
Garlic: Both minced and sliced to infuse deep aroma and flavor throughout.
Whole chicken (4 to 5 pounds): Fresh or thawed, make sure it’s patted dry for crispy skin.
Kosher salt: Essential for seasoning inside and out; adjust to taste.
Freshly cracked black pepper: Adds a subtle heat that complements the creamy butter sauce.
Leeks: Trimmed and thinly sliced, they become tender and slightly sweet when roasted.
Lemons: Thinly sliced to layer in the pan, infusing a gentle citrus aroma throughout the dish.
White wine: Adds depth and acidity to the roasting pan sauce—dry white wine works best.
New potatoes: Small ones roast perfectly alongside without drying out.
Fresh tarragon: The star herb here, giving that distinctive, slightly licorice flavor in the sauce.
Salted butter: Added cold at the end for a silky finish to the leeks and potatoes.

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Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

One of the things I love about the Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe is how adaptable it is. You can easily swap ingredients or tweak it to suit your needs or the season.

Herb swaps: I sometimes swap tarragon for fresh rosemary or thyme depending on what I have – each herb gives the sauce a different character.
Vegetables: Adding carrots or parsnips along with the potatoes makes it even heartier in the colder months.
Mustard variations: If you like a spicier kick, Dijon mustard works beautifully instead of whole-grain.
Wine alternatives: For a non-alcoholic version, replace the white wine with chicken broth plus a splash of lemon juice.

How to Make Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe

Step 1: Prep the Mustard Rub and Chicken

Start by whisking together whole-grain mustard, olive oil, apple cider vinegar, brown sugar, and the minced garlic in a small bowl. This mixture is your magic sauce for the chicken skin—rub it evenly all over the chicken, making sure to get under the skin where you can, especially on the breasts for juicy meat. Then, season generously with salt and pepper. This step really helps develop that gorgeous golden crust.

Step 2: Arrange the Leeks, Lemons, and Wine in Your Roasting Pan

Take a large cast-iron skillet or a sturdy roasting pan and scatter the sliced leeks and thinly sliced garlic cloves across the bottom. Drizzle with olive oil, layer on lemon slices, and pour in the white wine. This bed of vegetables and wine will steam and flavor the chicken beautifully, and also later forms the base for a dreamy pan sauce.

Step 3: Roast Chicken and Potatoes Together

Place the chicken breast-side up on top of the leek and lemon bed. If you want neat presentation (I do!), tie the legs with kitchen string and tuck the wings under. In a bowl, toss the potatoes with olive oil and salt, then nestle them around the chicken. Pop everything into a 375°F oven. Roast for about 15 minutes per pound, which usually means around an hour and a half for a 4-5 pound bird. Start checking doneness with a meat thermometer when the skin is deeply golden and juices run clear.

Step 4: Finish the Sauce and Rest the Chicken

When the chicken is done, transfer it to a cutting board and let it rest for at least 10 minutes to seal in the juices. Meanwhile, stir fresh tarragon and cold butter into the hot leeks and potatoes in the roasting pan until the butter melts and the sauce is silky and fragrant. Spoon this luscious pan sauce over the carved chicken when serving.

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Pro Tips for Making Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe

Dry the Chicken Thoroughly: Patting the chicken dry before rubbing with mustard ensures crispier skin.
Use a Meat Thermometer: I learned the hard way that checking internal temp (165°F) beats guessing and guarantees perfectly cooked chicken.
Let the Chicken Rest: Resting lets juices redistribute, making every bite tender and juicy.
Room Temperature Ingredients: Bringing the chicken and butter to room temperature before cooking and finishing helps with even roasting and sauce emulsification.

How to Serve Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe

A whole roasted chicken with golden-brown, slightly charred skin covered in a shiny glaze sits in the center of a white pot. The chicken is garnished with small green herb leaves on top. Around the chicken, there are small, light brown potatoes and thin slices of lemon with pale yellow rings, mixed with light green and white chopped vegetables that look soft and cooked. The inside of the pot is cream-colored, and the pot itself has a light green handle. The background is a white marbled surface. Photo taken with an iphone --ar 2:3 --v 7 - Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard, Roast Chicken with Potatoes and Tarragon Mustard, Easy Roast Chicken Dinner, One-Pan Roast Chicken, Comforting Roast Chicken Meal

Garnishes

I like to sprinkle a bit of chopped fresh tarragon or parsley right before serving to add a bright pop of color and herbaceous freshness, which pairs perfectly with the rich sauce. A few lemon wedges on the side are great for guests who want an extra citrusy zip.

Side Dishes

This recipe is a full meal, but if you want to add something fresh, I recommend a crisp green salad dressed with a light vinaigrette or some steamed green beans tossed with a touch of garlic butter. Both add a nice contrast to the warm, hearty main dish.

Creative Ways to Present

For special occasions, I’ve served this whole roast chicken on a large wooden cutting board surrounded by roasted lemon halves and fresh herbs. It makes for a rustic, inviting centerpiece. You can also carve and serve family-style on a big platter with the potatoes and leeks piled high next to the chicken, so everyone can help themselves.

Make Ahead and Storage

Storing Leftovers

I usually store leftover chicken and vegetables in airtight containers in the fridge for up to 3 days. Make sure to keep the pan sauce separate or drizzle just before reheating to keep everything juicy and flavorful.

Freezing

While I don’t freeze whole roasted chicken often, the leftover carved meat freezes well when wrapped tightly in foil or freezer bags. Potatoes and leeks tend to get softer upon thawing, so I recommend reheating gently or enjoying leftovers fresh.

Reheating

The best way to reheat leftovers is to warm them in a 325°F oven covered with foil to prevent drying out, or gently in a skillet over low heat with a splash of chicken stock. This keeps the chicken moist and revives the potatoes without turning them mushy.

FAQs

Can I use chicken thighs or parts instead of a whole chicken for this recipe?

Absolutely! Chicken thighs or drumsticks work well if you’re looking for a quicker cook time or smaller portions. Adjust roasting time accordingly—generally 35-45 minutes at 375°F until the meat is cooked through and skin is crispy.
What can I substitute for tarragon if I don’t have any on hand?

If tarragon isn’t available, fresh thyme or rosemary also provide lovely herbal notes, though the flavor will be different. I’ve found that thyme works best for retaining a fresh, slightly sweet balance similar to tarragon.
How do I know when the chicken is fully cooked?

The safest way is using a meat thermometer inserted into the thickest part of the thigh (avoiding bone). When it reads 165°F (74°C), your chicken is perfectly cooked and safe to eat. The juices should also run clear when pierced.
Can I prepare this recipe ahead of time?

You can prepare the mustard rub and chop your leeks and potatoes a day ahead, storing them separately in the fridge. Then assemble and roast on the day you plan to serve for the freshest result.

Final Thoughts

When I first tried this Whole Roast Chicken with Potatoes, Leeks, and Tarragon Mustard Sauce Recipe, it quickly became a staple because it’s just so satisfying and easy to pull off without stress. The way the flavors blend and the simple process makes me feel like a kitchen rockstar every time. I can’t recommend it enough if you want a home-cooked meal that feels fancy, tastes incredible, and leaves your family asking for seconds—and maybe thirds. Give it a whirl and watch how it becomes your go-to for effortless, delicious dinners.