For the Burgers

1lb ground chuck
1lb ground round
1 medium sweet potato - cooked and mashed (microwave for 7-10 minutes then peel)
2 tablespoons of the spice mixture   *recipe below

Mix all ingredients in a bowl until well combined.  Form four patties from the beef, sweet potato and spice mixture.
Lightly oil and generously salt each side of the burgers.

On a hot grill set up for indirect cooking, place the burgers on section of the grill grates not over the flame. Cook for 5 minutes on each side.

Spice Mixture

1 tbl cumin
1 tbl garlic powder
1 tbl chili powder
1 tbl black pepper
1 teaspoon hot paprika
1 teaspoon smoked paprika
Mix all spices together