Classic Basic Gourmet Chicken Sandwich Filling

Begin by shredding the oven-baked chicken breasts into a large bowl.

Add the finely chopped celery and red onion to the shredded chicken.

Mix in the chopped chives and Dijon mustard, stirring until everything is evenly distributed.

Season with salt and pepper to taste.

Add the mayonnaise to the mixture, folding it in gently until all the ingredients are well incorporated.

Let the filling refrigerate for at least an hour before serving to allow all the flavors to meld together.

To assemble the sandwich, layer the lettuce or spinach onto a piece of whole grain bread, top with a generous scoop of the chicken filling, and then top with another piece of bread.

Slice and serve your gourmet chicken sandwiches immediately.