To get your veggie burgers to stick together when they are cooked, you will need to make sure that they are not too moist or too dry. Moist veggie burgers tend to fall apart when they are cooked, while dry ones tend to crumble apart when they are placed on a bun. You will need to make sure that your veggie burgers are well-formed before they are cooked, so they will not fall apart when they are being heated in a pan or oven. It is best to make sure that your patties are well-formed before they are put into a pan or oven to ensure that they will cook evenly and that they will not fall apart during cooking. It is best to cook veggie burgers on a pan rather than in an oven because they can get soggy when they are cooked in an oven.