Cooked Spinach Recipe

Ingredients: • 2 tablespoons butter • 1 small onion, finely chopped • 2 cloves garlic, minced • 1 pound fresh spinach, washed and trimmed (or 2 (10-ounce) packages frozen chopped spinach, thawed and drained) • 1 cup heavy cream • ½ cup grated Parmesan cheese • 1 cup shredded mozzarella chees