Warm the tortillas by heating a frying pan over medium heat. Place the tortillas in the pan for a few seconds on each side until warmed and soft. Remove and set aside.

In a mixing bowl, crack the eggs, add a pinch of salt and pepper, and whisk until well mixed.

In the same frying pan, add a little olive oil or butter. Once hot, pour in the whisked eggs and stir gently with a spatula as they cook. Cook until fluffy and slightly firm, about 3-4 minutes.

Add the diced tomatoes, onions, and grated cheese to the pan. Stir gently until the cheese melts.

Take the warm tortillas and fill each one with the egg mixture. Sprinkle fresh cilantro on top if desired.

Arrange your breakfast tacos on serving plates and enjoy them warm.