Whisk the egg and add it to a large bowl. Grate the onion and garlic cloves and add them to a bowl. They can be finely minced or substituted with 1 teaspoon of onion powder and 1 teaspoon of garlic powder.
Add the ground chicken, bread crumbs, and salt. Use your hands to combine all the ingredients in the bowl.
Divide the mixture in half, and then divide each half in half again, to yield 4 patties of similar size. Shape each into a round patty, approximately 1 inch thick. Then, set it on a plate and press down in the middle to ensure they cook evenly. You want the middles of your patty to be thinner because they take longer to cook. Spray or lightly grease both sides of the burgers.
Cook:
Heat a pan over medium heat for about 30 seconds. Once it's hot, place the chicken burger patties down where they'll cook, without moving them, for 5 to 6 minutes on the first side. Flip them over and finish cooking the second side for an additional 5 minutes.
In the grill, once it's been preheated, cook the ground chicken burgers for 5 to 6 minutes per side, with the lid closed, only opening the lid to flip them over and cook them for 5 more minutes.
When the chicken burgers are cooked through and the internal temperature has reached 165F, remove them from the pan onto a plate.
Assemble the chicken burgers with your favorite buns, dressed exactly how you want them.