Preheat the air fryer: Set it to 375°F (190°C) for 3–5 minutes. A hot basket helps the burgers brown.
Mix the turkey base: In a bowl, combine ground turkey, grated onion, olive oil, egg, breadcrumbs, Worcestershire, Dijon, garlic powder, onion powder, salt, and pepper.
Stir gently until just combined—don’t overmix.
Shape the patties: Divide the mixture into 4 equal portions. With wet hands, form 4 patties about 1/2 inch thick. Make a small indent in the center to help them cook evenly.
Prep the basket: Lightly spray or brush the air fryer basket with oil to prevent sticking.
Cook the first side: Arrange patties in a single layer with a little space between them.
Air fry at 375°F (190°C) for 7–8 minutes.
Flip and finish: Carefully flip. Air fry another 5–7 minutes, or until the internal temperature reaches 165°F (74°C). Thicker patties may need a minute or two more.
Optional cheese melt: Add a slice of cheese during the last 30–60 seconds and close the basket to melt.
Rest and serve: Let the burgers rest for 3 minutes.
Build your burgers on toasted buns with your favorite toppings and sauce.