1. Heat the oven to 400 degrees F and set a rack in the middle. Spread the cubed sweet potato on a large baking sheet and toss with the oil (or water), cumin, smoked paprika, and salt.

2. Roast the sweet potato for 20 to 25 minutes, until fork-tender with lightly caramelized edges. Set aside and drop the oven temperature to 350 degrees F.

3. While the sweet potato roasts, set a large cast-iron or metal skillet over medium heat. Add the kale and 2 tablespoons of water, cover, and steam for 4 to 5 minutes, until just softened but still bright green. Uncover and set aside.

4. Combine the drained black beans, steamed kale, and roasted sweet potato in a mixing bowl. Stir in the smaller amount of enchilada sauce so the filling holds together.

5. Wrap the tortillas in a damp cloth and microwave for about 30 seconds (or warm them on the oven rack for a few minutes) so they roll without cracking.

6. Pour about a third of the remaining enchilada sauce into the bottom of a 9 by 13 inch baking dish and spread it to coat.

7. One at a time, lay a tortilla in the sauced dish, flip it over so both sides are coated, fill with about a third of a cup of filling, roll, and place seam-side down at the edge of the dish. Continue with the rest, adding more sauce to moisten if needed. Spoon any remaining filling around the edges.

8. Pour the rest of the enchilada sauce in a stripe down the middle (use less for slightly drier enchiladas, more for tender, saucy ones).

9. Bake at 350 degrees F for 15 to 20 minutes, until heated through. Scatter with cilantro and serve with avocado, guacamole, or avocado crema.