1. Whisk eggs with yogurt, add a little salt and pepper (the cheese is also salty).
2. Cut the tomato into cubes, grate the cheese on a coarse grater.
3. Grease a frying pan (24 cm in diameter) with butter. Pour in the egg mixture, close the lid. Cook over medium heat.
4. When the omelet is fried from the bottom, turn it over with a wide spatula. Put tomatoes on it, sprinkle with cheese and basil.