In a large skillet over medium heat, cook the diced onion until soft.
Add the ground turkey and cook until browned, breaking it apart with a spoon.
Stir in ketchup, tomato paste, Worcestershire sauce, mustard, garlic powder, onion powder, salt, and pepper.
Add water, mix well, and let it simmer for 10 minutes until thickened.
Serve the turkey mixture on hamburger buns.