### Instructions
1. **Prepare the Chicken:** If you don’t have cooked chicken on hand, you can boil, bake, or pan-fry chicken breasts until cooked through, then shred or dice them. Allow the chicken to cool completely before proceeding.
2. **Combine Wet Ingredients:** In a medium-sized bowl, whisk together the mayonnaise, Dijon mustard, and lemon juice until smooth.
3. **Add Flavorful Veggies:** Stir in the finely chopped celery, red onion, and fresh chives into the mayonnaise mixture.
4. **Fold in Chicken:** Add the shredded or diced chicken to the bowl. Gently fold everything together until the chicken is evenly coated with the creamy dressing.
5. **Season to Perfection:** Season the chicken salad with black pepper and salt to taste. It’s always a good idea to taste and adjust the seasoning here as preferences vary.
6. **Assemble Your Sandwich:** Toast your bread if desired. Spoon a generous amount of the creamy chicken salad onto one slice of bread.
7. **Add Optional Toppings:** If using, layer on lettuce leaves, tomato slices, or avocado slices.
8. **Complete the Sandwich:** Top with the second slice of bread. Press down gently and slice in half if desired. Serve immediately and enjoy your incredibly delicious creation!
### Short Tips
* **Make it Ahead:** The chicken salad can be made a day in advance and stored in an airtight container in the refrigerator. The flavors actually meld beautifully overnight!
* **Vary Your Herbs:** Don’t have chives? Try fresh dill, parsley, or a touch of tarragon for a different flavor profile.
* **Spice it Up:** Add a pinch of cayenne pepper or a dash of hot sauce if you like a little kick.
* **Texture Boost:** For extra crunch, mix in some toasted pecans or sliced almonds.
* **Leftover Chicken Magic:** This recipe is fantastic for using up leftover rotisserie chicken or any cooked chicken you have on hand.
