As in, 'He got his just deserts.'
Note the spelling, because until recently I was one among many who thought it might perhaps be spelt 'dessert'. This is not the case. Apparently we are all victims of the punning business name industry, responsible for hairdressers named Curl up and Dye, and, yes, about a million sweets cookbooks called Just Desserts.
Desserts is pronounced the same way, and I suppose it makes some kind of intuitive sense because desserts are often used as a reward (though not so often as punishment).
I've said it before and I'll say it again: a pun is a very dangerous thing.