1. Drain the liquid from cans of salmon, and the very fish crush with a fork. Boil eggs and cut into cubes. Processed cheese (chilled) and tomatoes cut into cubes.
2. Onions cut into half rings, and not too bitter to pour boiling water for 10 minutes, then rinse with cold water. Mix eggs, cheese, salmon, tomatoes and onions. Refill with mayonnaise, salt and pepper.