In the
US, a
pizza is assumed to include the
crust, a
tomato sauce, and
mozzarella made from
cow's
milk. Other
toppings can be ordered for a small charge, usually about 10% of the cost of the pizza itself.
The following toppings are available from at least one national pizza chain:
Meat and Fish
Vegetables, Fruits, Herbs, Fungi, etc.
Other
Less common toppings include artichoke, basil, sun-dried tomatoes, feta, and other Mediterranean fare.
(Did I miss your favorite topping? /msg me!)