Creating a Classic Chicken Salad Sandwich is simple when you follow these steps:

1. Cook the Chicken: If using raw chicken, boil or poach it until fully cooked. Let it cool, then shred or dice into bite-sized pieces.
2. Prepare the Dressing: In a large bowl, combine the mayonnaise, Dijon mustard, and lemon juice. Mix well until smooth.
3. Add the Chicken: Fold the cooked chicken into the dressing mixture until thoroughly coated.
4. Incorporate Vegetables: Add the chopped celery, grapes, red onion, and nuts (if using). Stir gently to combine.
5. Season: Taste the mixture and add salt and pepper as needed.
6. Chill: For best flavor, cover and refrigerate the chicken salad for at least 30 minutes. This allows the flavors to meld beautifully.
7. Prepare the Bread: Slice your bread of choice and lay lettuce leaves on one side of each slice.
8. Assemble the Sandwich: Spoon a generous amount of chicken salad onto the lettuce-covered bread. Top with another slice of bread.
9. Serve: Cut the sandwich in half or quarters, if desired, and serve immediately.

These steps will guide you in creating this incredible sandwich with ease!