How to Make It
In a large pot, cover the chicken breasts with water. Bring to a gentle simmer and cook for 15 to 20 minutes, or until cooked through. Remove the chicken from the water and let cool. Cut into 1/2-inch pieces and set aside.
In a large bowl, combine the mayonnaise, mustard and chili powder. Stir in the chicken and celery. Season with salt and pepper, to taste.
Assemble the sandwiches with your choice of bread, chicken salad mixture and toppings.