In a food processor, add Boneless, Skinless Chicken Breast (3), Egg (1), Salt (1/2 teaspoon). Pulse until the mixture is smooth.
In a bowl, add Corn Starch (1 cup). Using wet hands, shape the chicken patties, making them slightly larger than the bun and just under 1-centimeter thick. Coat them on both sides and set aside.
In a large mixing bowl, add Water (1 cup), All-Purpose Flour (1 cup), Corn Starch (1/2 cup), Egg (1), Yellow Mustard (2 tablespoon), Garlic Powder (1 tablespoon), Onion Powder (1 tablespoon), Salt (1/3 tablespoon), and Ground Black Pepper (1 teaspoon). Whisk until the batter is smooth.
Coat the chicken patties in the batter. Remove the excess and place on a baking tray lined with baking paper. Place in the freezer for 1-2 hours to harden.
To make the sauce, in a small mixing bowl, add Mayonnaise (1 cup), Dry Mustard (1 teaspoon), Onion Powder (1/2 tablespoon), and Salt (1/2 teaspoon). Mix well and set aside.
In a deep-fryer or large saucepan, add Canola Oil (to taste) and heat to 350 degrees F (175 degrees C).
Fry chicken patties for 5 minutes.
Transfer patties to a paper towel-lined plate for 3 minutes to rest.
Fry patties once more for 5 minutes, or until golden brown on the outside. Drain and pat dry with paper towels.
Microwave Hamburger Bun (to taste) for 20-30 seconds.
On the heel bun, place chicken patty. On the crown, spread the special sauce and top with Iceberg Lettuce (to taste).
Serve immediately with any side you choose!