Place the ground turkey, garlic, chipotle chili powder, oregano, salt, and black pepper in a large mixing bowl. Lightly mix with your fingers, just until combined. Fold in the grated sweet potato and cilantro. Form the mixture into patties that are about 1/2-inch thick (4 to 6 patties total).

Meanwhile, generously drizzle a cast iron pan or other large, non-stick skillet with olive oil and heat over medium. Once hot, place the patties on the skillet and cook for 2 minutes on the first side, flip then cook 1 additional minute. With a cover for the skillet ready in one hand, pour a little water into the skillet, then cover it quickly, being careful as the oil will sputter. Let the burgers cook steam until cooked through, about 5 minutes. Towards the end of the cooking time, top with grated cheddar cheese, then recover and allow the cheese to melt.

Serve the burgers on toasted whole wheat buns, topped with sliced avocado, salsa, and sour cream as desired. Enjoy immediately.