Boil eggs hard, cut finely. Chop the onion very finely. Cut the chives into small rolls. Put the lettuce mayo, mustard, salt and pepper in a bowl and mix well.
I usually make this dip the day before and put it covered in the fridge. Fresh bread or baguette is ideal as a base. The hit at every party. I also like to use it to prepare sandwiches and as a decoration I sprinkle chives on each sandwich.