Preheat oven to 400°F/200°C, combination steam setting. If your oven has variable steam settings, use 50%. If not, don’t worry! Just set to combi steam at the correct temperature and the oven will work out the humidity for you.

Toss the sweet potatoes with the olive oil, salt, spices, onion, garlic and chili powders until all the cubes are evenly coated. Spread this mixture out in a parchment paper-lined shallow pan. Use two pans if you need to – the sweet potato should be in a single layer.

Roast the sweet potatoes for 20 minutes. While they’re cooking, drain the black beans of most of their liquid. You want to try to leave behind around 2-3 tbs liquid. Put the beans and liquid into another pan and when the 20 minutes is up for the potatoes, add this pan to the oven. Set your timer for a further 5 minutes, by which time the beans should be hot and sweet potatoes tender and browned at the edges.

Put the sweet potatoes into a warmed bowl and set aside. Roughly mash the beans directly in the pan. I find a potato masher easiest for this but a fork will work too. You want them to be mostly crushed but with a bit of texture left. Taste and add a little salt if you need to (I never do, the salt from the canning liquid seems to be enough, but you do you). Put the beans into another warmed bowl.

Mix together the red cabbage, scallions, mayonnaise, a pinch of salt and the juice of a lime. You can do this up to a couple of hours ahead but the cabbage will bleed its color, so I prefer to do it at the last minute. Cut the remaining limes into wedges for serving.

Put the sweet potato, beans, dressed cabbage, feta and any other accompaniments on the table, along with the warmed tortillas. You can either make up the tortillas and serve, or, my preference, let everyone help themselves and add as much or as little of each filling as they like.

Prepare exactly as per the method above, except:

In step 1, preheat oven to 400°F/200°C.

In step 3, cook the sweet potatoes for about 30 minutes, and the beans for about 10 minutes.