Receta Beef Spinach Casserole

1 pound ground beef 1 medium onion, chopped 2 garlic cloves, minced 1 can (4 ounces) mushroom stems pieces, drained 1 teaspoon salt 1 teaspoon dried 1/4 teaspoon pepper 2 packages (10 ounces each) chopped spinach, thawed and squeezed dry 1 can (10-3/4 ounces) cream of celery soup, undiluted 1 cup (8 ounces) sour cream 2 cups (8 ounces) mozzarella cheese, divided In a large cook beef, onion and garlic over medium heat until the meat is no longer drain. Stir in the mushrooms, salt, basil and pepper. Add the spinach, and sour cream. Stir in half of the mozzarella cheese. Transfer to a 2-qt. baking dish. Bake, uncovered, at 350° for 15 minutes. Sprinkle with remaining cheese;…