Peel onions and garlic. Dice onions, chop garlic finely. Fry both in 1 tablespoon of oil. Add tomatoes and season with 1 dash of vinegar, salt, pepper and sugar. Let the sauce simmer for about 15 minutes. Meanwhile rinse rice well and cook in boiling salted water with a pinch of turmeric for about 13 minutes.
In the meantime, chop the coriander finely, except for some garnish. Drain the rice and mix with the tomato sauce. Fold in the coriander and season to taste with turmeric. Heat the rest of the olive oil and fry the prawns briefly. Arrange with tomato rice and serve garnished with coriander