Preheat the oven to 400°F and lightly grease a sheet pan with olive oil. Arrange the sweet potato rounds on the pan in a single layer and season with salt and pepper. Roast for about 20 minutes, or until tender when pierced with a fork.
While the sweet potatoes are roasting, make the burgers. Divide the ground beef into eight equal portions and flatten them into patties. Season them generously with salt and pepper on both sides.
Heat a large heavy skillet over medium-high heat. Add the burgers and cook for 5-7 minutes, until well browned on the bottom, then flip and top with cheese. Cover the pan and cook for 3-8 minutes on the second side, or until the burgers reach your desired doneness. Transfer the burgers to a plate and rest for five minutes.
Finally, place half of the sweet potato rounds first with a bit of lettuce and a patty, followed by sliced onion, avocado, and tomato. Top with the remaining sweet potato rounds. Secure with toothpicks if desired and serve hot.
*You can use the mouth of a small jar or drinking glass to cut out little rounds of cheese from big slices.
Notes
Substitutes:
Instead of beef, you may use ground chicken or turkey
Any neutral oil will work
Use your favorite low-fat cheese
Storage:Place leftovers in a container and store in the fridge for up to 3 days. Reheat in the microwave when ready to eat. You can freeze for up to 3 months.Nutritional facts:Please keep in mind that the nutritional information is calculated using a nutrition facts calculator. It is a rough estimate and can vary greatly based on products used.