Preheat oven to 400°F. Evenly slice sweet potatoes into thin rounds, about 1/4 inch thick, using a sharp knife, mandolin, or food processor.*
Place the slices flat on parchment-lined greased baking sheet in a single layer (may need 2 baking sheets, don’t want to overcrowd). Mix the black pepper, garlic powder and chili powder in a small bowl. Lightly brush (or use spray oil) sweet potato with neutral oil and then sprinkle the seasoning mixture evenly over the sweet potato rounds.
Bake sweet potatoes 25-35 mins flipping half way. The time will depend on how thin they are sliced. Be sure to watch them to make sure they don’t burn- it can happen quickly.
While the sweet potato chips are cooking, brown meat until fully cooked, drain and set aside. Heat olive oil in a large pan. Once hot, add onion and red pepper, sauté until translucent and just starting to brown. Add the garlic and sauté until fragrant, 1-2 minutes.
Mix the cornstarch with the taco seasoning mixture in a small bowl. To the pan add black beans, cooked turkey, taco seasoning mixture and water. Bring to a low simmer, letting it thicken for 15 minutes or until sweet potatoes are done roasting. Be sure to taste and add more seasoning to your liking. I added an additional teaspoon of chili powder for more spice.
Remove the sweet potatoes from the oven. Transfer all of your baked sweet potato chips to one tray, they shrink down quite a lot when cooked and will fit on one tray. Arrange and slightly overlap the sweet potatoes, filling in empty spaces on the tray.
Top the sweet potatoes evenly with meat mixture, then the shredded cheese. Place uncovered back into the oven to bake about 2-3 minutes, or until cheese is melted.
Once the cheese has melted, remove from the oven. To serve, top with additional garnishes (scallions, red onion, jalapeno, cilantro). Serve with guacamole, Greek yogurt and salsa.