Mash the eggs in a bowl. Add mustard, mayonnaise, salt and pepper and mix well.
Assemble sandwiches.
Store leftover egg salad in the refrigerator for up to 5 days, depending on the freshness of the eggs.
Notes
Other Variations:
Add celery: 1 celery rib, dicedAdd onion: 2 Tbsp chopped green or red onionAdd pickles: 1 Tbsp diced dill picklesAdd avocado: mashed avocado or top with avocado slicesMake it a BLT: Add bacon, lettuce and tomato for a egg salad BLT sandwich