Grind the roasted turkey in a blender. You can use boneless skinless meat from the thigh, legs or breast. Transfer to a large bowl. Grind the peeled onion in a blender and transfer into the same bowl.
Add eggs, salt and spices to the bowl. Pour in your Greek yogurt, breadcrumbs and a few pinches of black pepper. Mix everything thoroughly with a spatula until incorporated.
Preheat the air fryer to 400F for 5 minutes. Line basket with parchment paper and spray with olive oil. With wet hands, make patties and place on parchment paper. Bake 8 minutes.
After the 8 minutes, the patties will become golden in color. Carefully flip each one to the other side and bake for another 3 minutes. (timing will depend on how large you made your patties)
Fried: Add 2 tbsp of olive oil into your skillet over medium/high heat. Add patties and heat a few minutes on each side until browned and cooked all the way thru. Set on paper towels when done to absorb excess oil and serve.
Serve the patties hot, with sauce or sour cream on sauce and a side of vegetables.