Tacos of greens and black beans in red chile sauce

Pull the stem ends off the guajillo chilies, open them and shake out the seeds; pull out any seed pod stuck at the top.

Toast the chilies in oil in a large saucepan, turning, until they change colour and smell toasty.

Collect the chilies in a bowl, cover with hot tap water, lay a plate on top to keep them submerged, and rehydrate 20 to 30 minutes until very supple.

Blend the chilies with about two-thirds cup of the soaking liquid, raw garlic, a little black pepper and a little crushed Mexican oregano until smooth.

Return the chili-toasting pan, with its oil, to medium-high heat. Add the puree all at once, pressing it through a medium mesh sieve.

Stir 4 or 5 minutes until reduced to the consistency of tomato paste.

Add three-quarters of a cup of water, turn the heat way down, and simmer a few minutes.

Cut the chard stems crosswise, and the leaves crosswise into about half-inch pieces.

Season the sauce with about a teaspoon of salt and about half a teaspoon of sugar to bring out the chilies' fruitiness.

Add the drained black beans, then the chard stems, then the sliced leaves. Cook a few minutes until the greens wilt into the sauce.

Serve in tacos sprinkled with a little queso fresco.