Put butter in a saucepan. Add onion and shake until the onion is soft, but not brown. Then add Spanish peppers, red pepper and tomatoes; the tomatoes should be in rather solid pieces. Add a seasoning of pepper and salt. Let this cook slowly while you shir the desired quantity of eggs. When the eggs are ready to serve, put two tablespoonfuls of this sauce at each side of the dish, and send at once to the table.