In a large bowl, mix the turkey with the onion soup mix, pepper, garlic powder, soy sauce, and egg. Refrigerate the mixture about 10 minutes, then form into 6 patties.
Preheat the grill for medium-high heat.
Lightly oil the grill grate. Place the patties on the grill. Cook for 20 minutes, turning once, or until well done. The inside of the burgers will look whitish in color when cooked through. Serve on buns.
