Ingredients
2 lbs boneless, skinless chicken breasts, thinly sliced
½ small onion, finely diced
2 cloves garlic, minced
8 oz mushrooms, sliced
4 tablespoons butter, divided
1½ cups chicken broth
¼ cup heavy whipping cream
½ teaspoon salt
½ teaspoon black pepper
⅛ teaspoon xanthan gum (optional, for thickening)
1½ cups mozzarella cheese, freshly grated
½ cup parmesan cheese, freshly grated
1 teaspoon Italian seasoning
Instructions
- Preheat the oven to 400°F. Grease a 9×13-inch casserole dish.
- In a large cast-iron or nonstick skillet, melt 2 tablespoons butter over medium-high heat. Add mushrooms, onion, and garlic. Sauté 8–10 minutes until mushrooms are tender and onions are translucent. Remove vegetables and set aside.
- Add remaining 2 tablespoons butter to the skillet. Sear chicken for 2–3 minutes per side, just until lightly golden. Do not cook through. Transfer chicken to the prepared casserole dish.
- Return vegetables to the skillet. Stir in chicken broth, heavy cream, salt, and pepper. Cook over medium heat for 5 minutes, stirring constantly.
- Turn off the heat and sprinkle xanthan gum over the sauce if using. Let thicken for 5–10 minutes.
- Pour the sauce over the chicken in the casserole dish. Sprinkle parmesan cheese first, then mozzarella. Top with Italian seasoning.
- Cover loosely with foil and bake for 10 minutes. Remove foil and bake another 8–10 minutes, or until cheese is melted and bubbly and chicken reaches 165°F. Broil 1–2 minutes for a golden finish, if desired.
- Let rest for 5 minutes before serving.
Notes
- Chicken Thighs: Boneless, skinless thighs are an excellent alternative. Bake uncovered at 400°F for 20–22 minutes after searing, then broil briefly if desired.
- Cheese Tips: Freshly grated cheese melts better than pre-shredded and creates a smoother sauce.
- Thickening the Sauce: Xanthan gum is optional. The sauce will still be creamy and flavorful without it.
- Avoid Overcooking: Lightly sear the chicken and finish in the oven to keep it tender.
- Make-Ahead: Store leftovers in the fridge up to 3 days. Reheat gently to prevent the sauce from separating.
- Prep Time: 10 min
- Cook Time: 45 min