Boil 4 eggs for 10–12 minutes
Cool the eggs in cold water
Peel the eggs
Chop the eggs into small pieces
Add 2 tablespoons mayonnaise
Add 1 teaspoon mustard
Add salt to taste
Add black pepper to taste
Mix until combined
Toast or use bread slices
Spread the egg salad on one slice of bread
Add lettuce if desired
Top with the second slice of bread
Cut the sandwich in half