Step 1

Preheat the oven to 350 degrees F (175 degrees C). Oil a baking dish.

Step 2

Combine flour, garlic powder, onion powder, paprika, poultry seasoning, salt, and black pepper in a large resealable plastic bag. Add chicken and toss to coat well. Shake off excess breading.

Step 3

Heat olive oil in a skillet over medium-high heat. Brown chicken on both sides, 5 to 10 minutes. Transfer to the prepared baking dish. Cook and stir potatoes in the same skillet until almost tender, 3 to 5 minutes. Transfer to the baking dish.

Step 4

Add butter to the same skillet over medium-high heat. Saute mushrooms for 2 minutes. Add green onions and garlic and saute until garlic is browned, about 3 minutes. Add soup, broth, and sherry. Bring to a boil and cook until sauce thickens, about 5 minutes. Add spinach and cook until wilted, 2 to 3 minutes.

Step 5

Pour sauce over chicken and potatoes in the baking dish. Top with mozzarella and Parmesan cheeses. Cover dish with aluminum foil.

Step 6

Bake in the preheated oven for 20 minutes. Remove aluminum foil and bake for 20 minutes more.