The term 'kitchen bulb' refers to three different vegetables that are commonly used in cooking. SHALLOT is a type of ONION with a milder flavor and a more delicate texture, which is often used in French cuisine. ONION is a vegetable that is widely used in many dishes, and it has a strong flavor and a crunchy texture. FENNEL is a vegetable with a mild licorice-like flavor, and it is often used in salads or as a garnish. All three of these vegetables are commonly used in the kitchen, and they can be used to add flavor and texture to a variety of dishes.