5 tilapia fillets (about 1 pound)
2 cups fresh baby spinach leaves
1/4 cup butter, cold and sliced into thin pieces
1/2 cup mayonnaise
1/2 cup sour cream
2 cloves garlic, crushed
1 teaspoon onion powder
1/2 teaspoon salt
1/4 teaspoon ground black pepper
1 cup mozzarella cheese, shredded
Preheat oven to 450 degrees Fahrenheit and grease a 9" x 13" casserole dish.
Lay spinach leaves along the bottom of the casserole dish in a thin layer.
Place the butter on top of the spinach, trying to get most of them lined up in the center with at least an inch in between pieces.
Lay tilapia pieces on top of butter.
In a small bowl combine mayonnaise, sour cream, garlic, onion powder, salt, and pepper. Pour over the tilapia pieces.
Sprinkle entire dish evenly with mozzarella cheese.
Place casserole dish into the oven and bake for 15 minutes, or until fish is cooked, the entire dish is hot throughout, and the cheese has melted.