Prepare the Eggs: Start by boiling two eggs in a small pot. Once hard-boiled, cool them in cold water, peel, and chop them into small pieces.
Mix the Base Ingredients: In a medium mixing bowl, combine the drained tuna, chopped hard-boiled eggs, mayonnaise, and Dijon mustard. Mix well until creamy.
Add the Crunch: Stir in the chopped celery and red onion. This adds a delightful crunch and freshness to your salad.
Season: Sprinkle in salt and pepper to your liking. Taste and adjust based on preference.
Serve: You can serve it immediately on a bed of fresh lettuce leaves, or scoop it onto your favorite bread for a scrumptious sandwich!