Aluminum foil is a versatile tool in vegetarian cooking. Use it to wrap vegetables for steaming, such as foil packets with potatoes, carrots, and bell peppers. It can also be used to line baking sheets for easy cleanup when roasting vegetables like Brussels sprouts, sweet potatoes, or eggplant. Foil can be used to create a makeshift 'oven bag' for steaming tofu or tempeh, enhancing flavor and moisture retention. Additionally, it's great for covering food to keep it moist during grilling, such as grilled vegetables or tofu. Always ensure the aluminum foil does not come into direct contact with an open flame to avoid burning.