- In a medium, heavy skillet on medium, heat olive oil. (Tip: A cast iron skillet works well for this use; avoid using nonstick if possible.)
- Add onion and stir to coat. Season with 1/8 tsp salt and 1/4 tsp pepper and cook, stirring occasionally, until very tender and lightly browned, about 20 minutes. Reduce heat if onion starts to brown too quickly or sticks to the pan. Transfer to a bowl and set aside.
- Heat an outdoor grill to medium-high and lightly brush grate with cooking oil. In a large bowl, combine turkey, remaining 1/4 tsp salt, remaining 1/2 tsp pepper, chile powder and garlic-herb seasoning. Form into 4 ½-inch-thick patties; indent each patty in center with your fingers. Grill, flipping patties halfway through, until no longer pink in center and internal temperature reaches 165°F on an instant-read thermometer, about 10 to 12 minutes. Just before patties are done, top each patty with 1 cheese slice and allow to just melt.
- Burgers can also be prepared in the oven under the broiler on a greased, foil-lined baking sheet. Broil on high for about 10 minutes, flipping halfway, until cooked through. Remove from oven, top with cheese slices and let rest for 3 to 5 minutes.)
- Meanwhile, prepare Thousand Island dressing: In a medium bowl, combine all dressing ingredients and stir until Sucanat has dissolved, about 1 minute. Divide spinach, caramelized onions, patties and dressing among buns.
- Calories 0
- Carbohydrate Content 0 g
- Cholesterol Content 0 mg
- Fat Content 0 g
- Fiber Content 0 g
- Protein Content 0 g
- Saturated Fat Content 0 g
- Sodium Content 0 mg
- Sugar Content 0 g
- Monounsaturated Fat Content 0 g
- Polyunsaturated Fat Content 0 g