1Place the 8 large eggs in a pot and cover them with water. Bring to a boil over medium-high heat.
Once boiling, remove the pot from heat and cover. Let the eggs sit for 10-12 minutes.
Drain the hot water and transfer the eggs to a bowl of ice water. Let them cool for about 5 minutes.
Peel the eggs and chop them into small pieces.
In a large bowl, combine the chopped eggs, 1/4 cup mayonnaise, 1 tablespoon Dijon mustard, 1/4 cup finely chopped celery, 1/4 cup finely chopped red onion, 1 tablespoon chopped fresh dill, 1 teaspoon lemon juice, salt, and black pepper to taste.
Mix everything together until well combined.
Toast the 8 slices of whole wheat bread if desired.
Spread the egg salad mixture evenly onto 4 slices of bread. Top with the remaining 4 slices to form sandwiches.
Serve immediately or refrigerate for later.