A creamy Sweet Potato & Spinach Gratin featuring roasted sweet potatoes, tender spinach, and melted cheese for a wholesome, comforting meal.
2 large sweet potatoes, peeled and diced
4 cups fresh spinach, roughly chopped
1 medium onion, finely chopped
3 cloves garlic, minced
1 cup milk
1/2 cup heavy cream
1/2 teaspoon nutmeg
1/2 teaspoon paprika
1/2 teaspoon salt
1/4 teaspoon black pepper
1 cup shredded mozzarella cheese
2 tablespoons olive oil
1/4 cup grated Parmesan cheese (optional)