Sour Cream Smothered Chicken

Name: Sour Cream Smothered Chicken
Cuisine: American
Ingredients: 4 tablespoons butter, divided; 4 tablespoons olive oil, divided; 1 medium onion, thinly sliced; 8 ounces mushrooms, sliced; 2 cloves garlic, minced; sea salt and black pepper, to taste; 1 1/2 pounds chicken breasts (4 total); 1 cup chicken stock; 1 cup sour cream; 1/3 cup shredded mozzarella cheese; 6 green onions, sliced; 6 slices bacon, cooked crisp and crumbled