I saw this on Diners, Drive Ins and Dives and thought I could recreate it fairly well.  From what I remember I did the following:

Roasted off two seasoned (salt, pepper and garlic) boneless skinless chicken breasts (think next time use some thigh too) on a rack.

Cool and dice chicken; reserve the liquid that gathers to add to concoction.

Scoop out two avocados to the diced chicken.  Mash together thoroughly until creamy.

2 tsp dijon mustard (Optional, but tasted very good)
2 Tbsp mayo
1 good healthy squirt of wasabi mayo (substitute more mayo in place, if desired)

Mix all together well, cover and chill for about 1 hour prior to serving.

Place about 1/4-1/3 cup mixture on toasted bread or buns.  Or, top your favorite salad greens with the mixture.