Boil the desired amount of rice in salted water and drain or steam it.
While the rice is cooking, peel and dice the onion. Wash, clean and chop the tomatoes. Fry the onion, add the tomatoes. Let simmer until a smooth mass has formed.
Now crumble and add the feta cheese, let it melt, stir if necessary and season with salt and pepper. Serve with the rice.