White pizza is pizza made without tomato sauce, using a base of olive oil, garlic, and often ricotta or another soft cheese instead. It should not be confused with Roman pizza bianca, a plain olive-oil-and-salt flatbread sold as a snack food; American white pizza is a fully topped pie, usually finished with mozzarella and toppings like spinach, mushrooms, or rosemary. It is especially common at pizzerias in the northeastern United States, where versions may add garlic, spinach, or clams. Because there is no tomato acidity to balance the richness, a well-baked, crisp crust and restrained cheese matter more than on a typical pizza.