Martha Stewart Egg Salad Sandwich

10 hard-boiled egg whites
2 hard-boiled egg yolks
1 avocado, 1/2 mashed, 1/2 roughly chopped
2 tablespoon(s) light mayonnaise
1 teaspoon(s) Dijon mustard
1 tablespoon(s) freshly squeezed lemon juice
Coarse salt
Freshly ground pepper
12 slice(s) white sandwich bread (such as Pullman), sliced about 1/2-inch thick, toasted

Using a pastry blender or fork, mash together egg whites and yolks in a large bowl; carefully fold in avocado. Stir in mayonnaise, mustard, and lemon juice; season with salt and pepper.
Place 6 slices of bread on a work surface. Evenly divide egg salad among bread slices. Add lettuce greens or tomato, if desired. Top with remaining 6 slices bread.

What do you do with the 8 leftover egg yolks? Leave it to Martha!

I wondered about that as well, and I could not think of anything. She probably threw them away.