This is yet another recipe from my mom. Please note: This is very oniony! If you don't like onions, you can replace them with the same amount of finely chopped celery.
Zesty egg salad (makes enough for 2 sandwiches)
1-1/2 tablespoons finely chopped onion
1 small Roma tomato, finely chopped
2 finely chopped green onions
2 hard-boiled eggs, chilled and chopped
about 1/8 cup mayo
salt and pepper, to taste
optional: 1/2 teaspoon chopped fresh parsley
Mix ingredients together gently.