Preheat oven to 225 degrees F (107 C) - use convection bake if you have it - and prep kale by rinsing, thoroughly drying, and tearing into small pieces (discard any large stems).
Add kale to a large mixing bowl and drizzle with oil. Use hands to massage the kale to disperse the oil.
Add salt, pepper, chili powder, cumin, and nutritional yeast (optional) to the kale and toss with hands to distribute.
Divide kale between 2 large baking sheets (amount as original recipe is written // adjust if altering batch size) and spread into an even layer, making sure the pieces aren't overlapping to ensure crispiness. You may need to bake them in 2 batches (or more if increasing batch size) depending on size of baking sheets.
Bake for 15 minutes. Then remove from oven and toss/stir to ensure even baking. Bake for 5-10 minutes more or until chips are crispy and slightly golden brown. Watch carefully to ensure they don't burn.
In the meantime, add slightly drained black beans to a small saucepan along with cumin and chili powder (add salt if beans are unsalted) and warm over medium heat. Once bubbling, reduce to low to keep warm. Stir occasionally.
Heat a large skillet over medium heat. Once hot, add 1 Tbsp oil and spread to coat the surface. Then add sliced sweet potatoes in a single layer. Cover to steam.
Cook for 3-5 minutes, checking every couple of minutes to see if the undersides are brown. Once brown, flip to the other side, cover, and continue cooking until both sides are brown and potatoes are tender (about 7-8 minutes total). Set aside.
To serve, arrange kale chips on a serving platter and top with sweet potatoes, black beans, and any other desired toppings, such as avocado, salsa, cilantro, or red onion. Serves 2 as an entrée or 4 as a side (amounts as original recipe is written // adjust if altering batch size).
Store leftover sweet potatoes and black beans separately in the refrigerator up to 3-4 days. Store leftover kale chips in a well-sealed container at room temperature up to 3 days (though best when fresh).