Line a baking sheet with parchment paper. Finely grate the half medium yellow onion and squeeze out any excess moisture.

In a large bowl, combine the turkey, grated onion, minced garlic, mayonnaise, Worcestershire sauce, kosher salt, and pepper. Mix gently until just combined.

Divide the mixture into four equal portions and shape into 1-inch thick patties. Chill in the freezer for at least 20 minutes.

Preheat your grill for medium-high heat, aiming for 450–500°F. Clean the grates to prevent sticking.

Using a paper towel soaked in oil, carefully coat the grill grates.

Place the patties on the grill and cook for 6–7 minutes on one side, then flip and continue grilling for another 6–7 minutes. Check for internal temperature of 165°F.

Remove the patties from the grill and let them rest for a few minutes. Assemble on toasted buns with your favorite toppings.