1. Peel, slice and chop the tomato, dice the potato, and cut up the pimientos.
2. Chop the onion and fry it lightly in a little olive oil; add the peas, tomato, potato and pimientos, and continue cooking for a few minutes, stirring all the time with a spoon.
3. Beat the eggs, season well, and pour into the pan.
4. Cook the omelette shaking the pan occasionally. When one side is lightly and evenly browned, cover with a plate to turn the omelette, and cook the other side. Do not fold.
5. Serve hot, with tomato sauce.
6. Tip: This omelette is also delicious when served cold, and it is a favorite picnic dish in Spain. The omelette is left to get quite cold and is packed between 2 plates in the picnic basket. To serve, cut and place between slices of bread or rolls and butter, accompanied by salad.