Spaghetti topping is a popular dish that can be made with a variety of ingredients. The most common toppings are SAUCE, meatballs, and pesto. SAUCE is a liquid or semi-solid food typically made from a combination of ingredients such as tomatoes, herbs, and spices. Meatballs are small balls of ground meat, usually beef, pork, or a combination of the two, that are cooked in a SAUCE. Pesto is a SAUCE made from basil, garlic, olive oil, pine nuts, and Parmesan cheese. All three of these toppings can be used to create a delicious spaghetti dish.