2 to 3 pounds chicken thighs (8 pieces), with skin on (recommended)
3 cups fresh mushrooms, sliced
1/2 medium yellow onion, chopped
1/2 cup flour
1 teaspoon kosher salt
1/4 teaspoon ground pepper
2 tablespoons unsalted butter
2 tablespoons olive oil
1 cup sour cream
1 cup chicken broth
1/2 cup sharp cheddar, shredded
Preheat oven to 350°F. Spray a 13-by-9-inch casserole dish with cooking spray.
Combine flour, salt and pepper in a large freezer bag. Add chicken pieces, and shake until well coated.
Heat butter and olive oil in a large skillet over medium-high heat. Brown chicken on both sides, about 5 minutes per side. Transfer chicken to casserole dish.
Add onion to same skillet, reduce heat to medium, and sauté 2 to 3 minutes. Add mushrooms and sauté 2 minutes. Stir in sour cream and broth until heated through.
Pour sour cream and mushroom sauce over chicken. Sprinkle with cheese.
Cover casserole dish, and bake in preheated oven 40 to 45 minutes. Uncover, and bake 3 to 5 minutes to brown cheese. Serve immediately.