Pat the chicken thighs completely dry using paper towels; drying the skin is essential for crispiness. In a small bowl, combine the kosher salt, black pepper, and smoked paprika. Rub the seasoning mixture all over the chicken.

Place a large, oven-safe skillet over medium-high heat. Add 1 tablespoon of olive oil. Once shimmering, place the chicken thighs skin-side down. Sear for 6 to 8 minutes without moving, until the skin is deeply golden brown and very crispy.

Flip the chicken thighs over to the flesh side and cook for an additional 2 minutes. Remove the chicken and set aside on a clean plate, leaving the rendered fat in the pan.

Reduce the heat to medium-low. Add 1 tablespoon of unsalted butter (if too much fat remains, pour some off first). Add the minced shallot and cook for 2 to 3 minutes until softened. Add the minced garlic and cook for 1 minute until fragrant.

If using, pour in the ½ cup of white wine. Use a wooden spoon to scrape up any browned bits (fond) from the bottom. Let the wine simmer and reduce by half (2–3 minutes).

Pour in the 1 cup of chicken broth and add the fresh thyme. Bring to a simmer. Whisk in the Dijon mustard and whole grain mustard until smooth. Stir in the heavy cream until the sauce is uniform. Taste and season with additional salt and pepper as needed.

Return the seared chicken thighs to the skillet, placing them flesh-side down so the crispy skin remains above the sauce.

Transfer the oven-safe skillet to a preheated oven set to 375°F (190°C). Bake for 15 to 20 minutes, or until the chicken thighs reach an internal temperature of 165°F (74°C) when measured at the thickest part.

Remove the skillet from the oven. Let the chicken rest in the sauce for 5 minutes. Garnish generously with fresh chopped parsley before plating. Serve the chicken drizzled with the creamy Dijon pan sauce.