Preheat & prep: Preheat the oven to 400°F and line a large baking sheet with parchment paper. Cut the red onion in half from root to stem, then slice each half lengthwise into 1-inch wedges, keeping the layers intact (don’t separate them).
Season and roast the veggies: Add the onion slices to the sheet pan and brush both sides lightly with olive oil. In a bowl, toss the sweet potato cubes with olive oil and all of the sweet potato spices. Spread them evenly on the prepared baking sheet alongside the onions. Roast for 30 minutes, or until the onions are nicely toasted (but not burnt) and the sweet potatoes are fork-tender. Remove from oven. Reduce the oven temperature to 350°F.
2 orange sweet potatoes, 1 red onion, 2 tablespoon olive oil, 1 teaspoon ground cumin, 1 teaspoon paprika, 1 teaspoon ground coriander, ½ teaspoon ground cinnamon, ½ teaspoon garlic powder, ½ teaspoon onion powder, ¼ teaspoon cayenne, ½ teaspoon kosher salt
Make the black beans: While the vegetables roast, heat a pan over medium heat and add olive oil. Sauté the chopped white onion for about 5 minutes, then add the garlic and cook for another 2–3 minutes, until fragrant. Add the black beans and all the black bean spices, and cook together for 5–6 minutes, stirring occasionally. Taste and adjust seasoning as needed. For a softer texture, lightly mash some of the beans with the back of your spatula. Transfer the mixture to a large bowl.
1 tablespoon olive oil, ½ yellow onion, 3 cloves garlic, 2 (15 oz) cans black beans, 1 teaspoon ground cumin, 1 teaspoon ground coriander, 1 teaspoon chili powder, ½ teaspoon paprika, ½ teaspoon kosher salt
Combine the filling: When the sweet potatoes and onions are done, remove them from the oven and gently toss them together. Add them to the bowl with the black beans and lightly mix until somewhat evenly distributed.
Bake the tacos: Lightly oil a second sheet pan. Brush one side of each tortilla with oil and place them oil-side down on the sheet pan. Fill each tortilla with the sweet potato–black bean mixture and a sprinkle of shredded cheese. Fold the tortillas over. Bake for about 10 minutes, or until the shells are crispy and the cheese is melted. Tip: If the tortillas won’t stay folded, thats fine. Just bake the tacos for 2–3 minutes, remove from the oven, gently press fold them down. They will stay once warmed. Return to the oven to finish crisping. 1 cup shredded cheese, 12 tortillas, 2 tablespoon olive oil