Heat oil in a large pot over medium heat. Saute onions until browned; remove from pot and set aside. Add ground beef to pot, and cook until evenly brown. Add garlic and cook for 2 minutes. Stir in browned onions, and cook on high heat for 3-5 minutes. Stir in 1 cup of water. Reduce heat, cover, and simmer for 20 minutes.
Stir in ketchup, beef stock, and teriyaki sauce. Season with pepper, curry powder, garlic powder, and onion powder. Cover and simmer for about 2 hours.
Mix together 1 tablespoons flour and 1/2 cup water. Stir into stew and cook until thickened.