Although it is not customary to cook natto, natto may be prepared in food items like sushi or "donburi". "Donburi" is any Japanese dish served with rice in a bowl. Natto can be made into a donburi by adding natto and other items like tuna or egg to rice inside a bowl. "Nattojiru" is what people add natto to miso soup as a seasoning. Also Natto is used for topping when we eat Soba, Udon, Spaghetti, Okonomiyaki and so on.