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

Divide the ground turkey mixture into 6 even balls (approximately ⅓ lb each). Then form the balls into patties.

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

Preheat the griddle over medium high heat (approximately 400 degrees F).

Butter the buns and place them on the griddle for 2 minutes to toast them and then set them aside while you prepare the patties.

Spread the oil onto the grill and spread it around with a spatula.

Then place the turkey patties onto the grill.  Top each one with a piece on parchment paper and then firmly press down to smash the turkey into a thin patty with either a burger press or a large spatula and then discard the parchment paper.

Cook the patties for 2-3 minutes until the juices in the turkey start to raise to the top and the color starts to change. Then scrape under the patty to get under the caramelized parts and flip the patty.

Once flipped, do not smash down the patties again. Cook for 1-2 more minutes until the patties reach an internal temperature of 165 degrees Fahrenheit.

Place a piece of cheese on the patties to melt.

Add a lettuce leaf and onion slices 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 slices.  Serve warm and enjoy!