Preheat your oven to 400°F (200°C) and season your chicken thighs with salt and pepper.

Dredge the chicken thighs lightly in flour, tapping off any excess.

Sear the Chicken: In a large, oven-safe skillet, heat a bit of oil over medium-high heat. Place the chicken thighs skin-side down and cook for about 7 minutes until the skin is crispy and golden. Flip the chicken and cook for another minute. Remove and set aside on a plate.

Prepare the sauce: Add the butter to the same pan. Once melted, add the mushrooms and cook undisturbed for about 5 minutes, allowing them to brown. Then add the shallot and garlic, sautéing until fragrant, about 2 minutes. Season with salt and pepper to taste. Pour in the white wine, scraping the bottom of the pan to release any browned bits. dd in the Dijon mustard, chopped tarragon, heavy cream, and chicken broth. Let the mixture come to a gentle simmer. Season again to taste.

Return the Chicken to the Pan: Nestle the seared chicken thighs back into the sauce. Place the pan in the preheated oven and bake until the chicken reaches an internal temperature of 165°F (about 20 minutes).

Serve: Sprinkle with fresh tarragon and chives before serving.