First, pickle your onions by mixing them with the lime juice and zest in a small bowl with a squeeze of honey and a pinch of salt. Set aside.

Heat the olive oil in a heavy-bottomed pan over a medium-high heat. Fry the garlic until lightly golden, about 1 minute. Stir in the tomato puree, paprika, cumin and chipotle with a splash of water and stir to create a paste. Cook off for 2 minutes until fragrant.

Add the sweet potato and toss to coat in all of the spices. Pour in the chopped tomatoes and stock. Cover with a lid and simmer 20-22 minutes over a low-medium heat to allow the sweet potato to soften enough so that a knife can pierce through. Check half way through as you may need to add more water or stock.

Meanwhile, put all of the herby sour cream ingredients into a food processor (coriander stalks and all), pour the lime juice from the red onions into it too, then whizz until smooth. Season to taste.

Once the potatoes have softened, pour in the black beans with their bean stock. Stir to combine then simmer for a further 4-5 minutes. If using canned beans, you’ll need add more salt at this point. Bubble away until the chilli has thickened and is a rich, glossy consistency.

Spoon into bowls, drizzle over the yogurt and scatter over the pickled onions.