Rinse the quinoa with water to remove the bitter substances in the outer layers, pour it into plenty of boiling water and simmer for about 15 minutes. Meanwhile, cut the tomato into slices and the onion into medium-sized pieces.
Heat the olive oil in a pan. Briefly fry the onion pieces and the pressed garlic clove. Drain the quinoa well and add to the pan. Stir everything well and let fry for about 5 minutes. Then season generously with rock salt and pepper. Now distribute the tomato slices on the quinoa mixture with little space between them and sprinkle the sesame seeds on top. Cook for another 5 minutes over low heat with the lid on.