Step 1

Prepare the Chicken: Dry chicken with clean paper towels. Season the thighs with salt and black pepper on both sides. Heat olive oil in a cast iron skillet over medium-high heat.

Step 2

Brown the Chicken: Add the chicken thighs to the hot skillet, skin side down (if using skin-on), and cook until browned, about 5-7 minutes per side, or until the thighs are cooked to an internal temperature of  155 to 160 degrees. Remove the chicken from the skillet and set aside.

Step 3

Cook the Shallot: In the same skillet, add the chopped shallot and cook until softened and fragrant, about 2-3 minutes, scraping any brown bits from the bottom of the pan.

Step 4

Deglaze the Pan: Pour in the dry white wine (chicken broth or water) to deglaze the pan, scraping up any browned bits from the bottom.

Step 5

Prepare the Sauce: Reduce the heat to medium-low and add the heavy cream, Dijon mustard, whole grain mustard, and salt. Stir to combine. Simmer the sauce for about 3-4 minutes, or until slightly thickened. Stir in the freshly grated Parmigiano cheese until melted and smooth.

Step 6

Combine Chicken and Sauce: Return the chicken thighs to the skillet, skin side up, and spoon some of the sauce over the top. Simmer the chicken in the sauce for an additional minute or so.

Step 7

Garnish and Serve: Sprinkle the chopped fresh tarragon (or parsley) over the chicken. Serve the chicken thighs hot with the creamy mustard sauce spooned over the top.