Sweet potato nachos

Preheat the oven to 220°C, gas mark 7. Using a fork, prick the sweet potatoes all over, then microwave on high for 8-10 minutes, turning halfway. Cut into chunks when cool enough to handle.

Line a large baking tray with baking parchment. Add the sweet potatoes, season then toss with 1 tbsp oil and spread into an even layer. Bake for 30 minutes, until golden and caramelised, smashing the pieces with a spatula to create more surface area halfway. Sprinkle the cheese over for the final 2 minutes of cooking time.

Warm 1 tsp oil in a medium pan over a medium heat, then add half the onions and sweat for 5 minutes. Stir in the chipotle paste and black beans with the water from the can. Lower the heat, simmer gently for 10 minutes until creamy, then season to taste. As it cooks, scrunch the remaining onion in a bowl with a pinch of salt and the juice of 1 lime, then set aside to macerate.

Mix the tomatoes, avocado and most of the coriander together with a little macerated onion and the remaining lime juice, then season. Layer the beans and avocado salsa over the cheesy sweet potatoes, then finish with soured cream and the pickled onions. Scatter with the remaining coriander, then serve in the tray at the table to share, with lime wedges for squeezing over.