Toppings on pizza are most typically ground meats and sausages, such as salami, pepperoni, ham, bacon and ground beef; fruits such as pineapple and olives; vegetable-like fruits such as chili peppers, sweet bell peppers and tomatoes; and vegetables such as onions. Mushrooms are also a popular topping.

Vegetable is a nutritional and culinary term denoting any part of a plant that is commonly consumed by humans as food, but is not regarded as a culinary fruit, nut, herb, or spice.

These include leaf vegetables (e.g. lettuce), stem vegetables (asparagus), root vegetables (carrot) and flower vegetables (broccoli), and botanical fruits such as green beans, cucumbers, squashes, pumpkins, tomatoes, avocadoes, capsicums, et cetera, as well as fleshy, immature seeds such as those of peas or beans.

Garlic (Allium sativum) is a bulbous perennial food plant of the family Alliaceae. The word comes to us from Old English garleac, meaning "spear leek".

The bulb has a strong and characteristic odor and an acrid taste, and when pure yields an offensively smelling oil, essence of garlic, identical with allyl sulphide (C6H10S2). Garlic is widely used in many forms of cooking for its strong flavour, which is considered to enhance many other flavours. Depending on the form of cooking and the desired result, the flavour is either mellowed or intense. It is often paired with onion and tomato. When eaten in quantity, garlic may be strongly evident in the diner's sweat the following day. The well-known phenomenon of "garlic breath" can be alleviated by eating fresh parsley and this is included in many garlic recipes. Because of its strong odor, garlic is sometimes called the "stinking rose".

Onion in the general sense can be used for any plant in the Genus Allium but used without qualifiers usually means Allium cepa L., also called the garden onion. Onions (usually but not exclusively the bulbs) are edible with a distinctive strong flavour and pungent odour which is mellowed by cooking. They generally have a papery outer skin over a fleshy, layered inner core. Used worldwide for culinary purposes, they come in a wide variety of forms and colors.

Onions may be grown from seed or very commonly from "sets". Onion sets are produced by sowing seed very thickly one year, resulting in stunted plants which produce very small bulbs. These bulbs are very easy to set out and grow into mature bulbs the following year, but they have the reputation of producing a less durable bulb than onions grown directly from seed and thinned.