Place the chicken meat into a food processor and pulse a few times to roughly chop. Continue pulsing for about 30 seconds until the chicken is finely chopped. If you turn "on" the food processor, your chicken will become a "paste".

In a bowl, combine the lemon juice, mayonnaise, salt, pepper, and Creole seasoning, and blend well. Add the chicken salad and chopped celery, and fold to combine.

Slice the avocados in half and remove the pit. Use a pairing knife to score the avocado or cut the center from top to bottom and crosswise without piercing the skin.

Scoop a portion of chicken salad into each avocado, covering the entire surface. Top with chopped tomato, if using.

Place 1 half into a compartmentalized lunch container and pack your choice of snacks into the empty compartments. Close the containers and pack them into lunch bags with an ice pack.

Refrigerate the remaining chicken salad in an airtight container for up to 4 days.