In a large mixing bowl, stir together the ground turkey, egg, salt, pepper, onion powder and garlic powder until well combined.  Use your hands to thoroughly mix the ingredients.

Divide the ground turkey mixture into 6 even balls (approximately ? lb each). Then form the balls into patties that are approximately 4 inches wide and 1 inch thick and make an indent in the center of each patty with your thumb.

Place the patties in the refrigerator (covered in plastic wrap) while you preheat the grill.

Preheat the Grill over medium high heat (approximately 450-500 degrees Fahrenheit). Rub oil on the grill grates to prevent the patties from sticking to the grill.

Place the patties on the grill over direct heat.  Cook for 4-8 minutes (flipping the patties halfway through the cook time) until the turkey patties reach an internal temperature of 165 degrees Fahrenheit. Use an instant-read meat thermometer to make sure that the patties are cooked to a safe temperature.

Place the buns on the grill and cook for 1 minute until they are browned slightly.  Watch them closely so that they do not burn.

Add a lettuce leaf to the bottom bun of each bun.

Remove the patties from the grill and add them to each  of the hamburger buns on top of the lettuce.

Then top each patty with the tomato and onion slices.  Serve warm and enjoy!