Cut the chicken thighs into bite-sized pieces.

Heat olive oil and 1 tablespoon of butter in a large skillet over medium-high heat.

Sear the chicken in batches until golden brown, about 5 minutes per side.

In the same skillet, add the remaining butter and sauté the chopped onion until soft and translucent, about 3-5 minutes.

Stir in minced garlic and allow to cook for 30 seconds.

Add the sliced cremini mushrooms and cook until golden, about 5-7 minutes.

Sprinkle flour over the mushrooms and cook for 1-2 minutes.

Stir in the Dijon mustard, then slowly pour in the chicken broth while stirring.

Allow the sauce to simmer until slightly thickened, about 3-5 minutes.

Stir in the heavy cream and return the chicken to the skillet, mixing well.

Simmer for an additional 5-7 minutes until the chicken is cooked through.

Season with salt and pepper to taste.

Garnish with fresh parsley and serve over mashed potatoes, noodles, or rice.