Peel and finely chop the onion. Peel the sweet potatoes and dice them. Place a medium-sized pan on a medium heat and add 1 tbsp oil and the chopped veg. Season with a pinch of salt and fry, stirring often, for 5-6 mins.

Peel and grate or crush the garlic. Finely chop the chilli, discarding the seeds and pith if you want less heat. Finely chop the coriander stalks, setting the leaves to one side for later.

Stir the garlic, chilli and coriander stalks into the veg. Add 1 tbsp Cajun seasoning. Cook, stirring often, for 2 mins.

Drain the black beans and rinse them. Tip them into the pan. Pour in the passata. Stir in 100ml water, then pop a lid on the pan and simmer for 15 mins till the sweet potatoes are tender, stirring every few minutes. Preheat your oven to 200C/Fan 180C/Gas 6.

Taste the black beans sauce and add a pinch more salt if you think it needs it. Lay 1 tortilla on your work surface and spoon 3 heaped tbsp of the sauce slightly to the left of the tortillas. Pick up the left side of the tortilla and roll it up to make a tube. Place the toortilla in a snug ovenproof dish.

Repeat with the remaining tortillas, till you have 4 tortilla rolls in the dish. Spoon the remaining black bean and sweet potato sauce over the top. Slide the dish into the oven and bake for 15 mins.

While the enchiladas bake, halve the avocado and scoop out the stone. Scoop the flesh out of the skin and either finely chop it or, if it is very soft, mash in a bowl using a fork.

When the enchiladas have baked for 15 mins, take them out of the oven. Divide between 2 warm plates and serve with the avocado and coriander leaves.