Preheat oven to 400 degrees F and place parchment paper on 2 -3 baking sheetsPlace sliced sweet potatoes on the prepared baking sheets, leaving a little space between them so that they don't touch.Lightly brush sides both sides of the sweet potatoes with oilSprinkle sweet potatoes with salt.Bake sweet potatoes for 20 minutes. Remove from oven. Gently turn chips over. Bake an additional 10 minutes until just turning crisp.Chips can be made ahead of time.Preheat oven to 350 degrees FIn a large oven proof skillet or rimmed baking sheet, spread sweet potato chips evenly (they will be overlapping)Top with beans, cheese, pepper, tomato and onion.Place skillet in hot oven for 7-10 minutes or until cheese is melted.Top with scallions, cilantro, jalapeño if using, and avocado.Serve with sour cream as desired.