Well, it depends on where you live, the climate and the soil over there. Now there are some vegetables that will grow from your kitchen scrap itself like Leeks, Scallions, Spring Onions and Fennel.
Plants like Celery, Bok Choi, Romaine Lettuce & Cabbage can be grown from the white root end. Same goes with Ginger, garlic, potatoes. There are quite a lot of vegetables that can be grown easily if you have the right climate and enough sunlight.