This spinach and mushroom casserole is a healthy and delicious way to enjoy your greens. Sautéed mushrooms and spinach are combined with garlic, onions, and a creamy sauce, then baked until bubbly and golden. The result is a flavorful and nutritious dish that can be served as a side or a vegetarian main course. Enjoy this casserole as a comforting and satisfying meal that is packed with vitamins and minerals.