For the Egg  Salad

6 hard-boiled eggs, peeled and chopped
1/4 cup  mayonnaise
1 tsp Dijon  mustard
1 tsp lemon juice
1 tbsp chopped chives (plus more for garnish)
Salt and pepper to taste
For the Sandwich:

4 slices of whole-grain or sourdough bread, toasted
Butter or lettuce leaves (optional)
DIRECTIONS