The term 'Pizza Ingredient' can be broken down into three crossword solutions: OREGANO (7 letters), Zees (4 letters), and TOMATO (6 letters). OREGANO is a fragrant, slightly bitter herb that is commonly used in Italian cuisine. It is often used to season pizza dough and as a topping for finished pizzas. Zees is a common abbreviation for mozzarella cheese, which is a type of cheese made from cow's milk. Mozzarella is a popular pizza topping due to its mild flavor and stretchy texture. Finally, TOMATO is a widely used vegetable that is often used as a topping for pizzas. It is known for its sweet and acidic flavor, and is also a source of lycopene, an antioxidant.