Heat a large skillet over medium-high heat and add a splash of oil. Season the chicken thighs with salt and pepper, and sear skin-side down for about 5-6 minutes until golden and crispy. Flip and cook for 4-5 minutes more, then transfer to a plate.

In the same skillet, reduce heat to medium and add chopped shallots and minced garlic. Sauté for 2-3 minutes until soft and aromatic. If using, add white wine and simmer for 1-2 minutes to deglaze the pan.

Stir in heavy cream, Dijon mustard, and whole grain mustard, mixing to create a smooth sauce. Allow to simmer for 3-4 minutes until slightly thickened.

Return the seared chicken thighs to the skillet, covering with the sauce. Simmer on low for about 20 minutes until the chicken reaches an internal temperature of 165°F and is tender.

Remove the skillet from heat and let sit briefly. Serve hot, garnished with fresh herbs if desired. Pairs well with potatoes, rice, or crusty bread.