Make your own food as often as possible. Buy fresh fruits and veggies and keep them on hand. Cravings are difficult, but you need to remind yourself of why you want to eat a vegan diet, or find a really strong reason. So after the craving has subsided, or you find some vegan appropriate food to consume, and you are thinking rationally, grabbing some nutrient dense food will usually curb whatever cravings your body has for a good while.
Some of my favorite things are 3 bean salad with spinach and broccoli.
red beans, black beans and grabanzos in a bowl with some fresh spinach and broccoli. You can toss in cucumber, carrots, or pretty much anything else that is tasty to you.
This is both nutrient rich, but also really yummy. You can top it with whatever dressing you enjoy.
I also recommend taking it easy on the carbohydrates. As a vegan/vegetarian, you may find yourself consuming a fair amount of carbs as an alternative to meat, dairy, cheese, and egg you would be eating otherwise. The modern western diet tends to be too carb heavy as it is, so try to pick foods with a larger variety of macro-nutrients.