Chop most of the coriander, leaving a few whole leaves to garnish. Juice the limes. Slice the red onions. Peel, deseed and thinly slice the butternut squash.
- 1 Heat the oven to 200°C/ 180°C fan/gas 6.
- 2 Combine the squash, chipotle chilli paste, garlic and olive oil in a roasting tray and roast for 35-40 minutes.
- 3 Meanwhile, put the sliced onion in a dish.
- 4 Heat the vinegar, sugar and 50ml water in a small pan.
- 5 Bring to the boil, then pour over the onion.
- 6 Set aside to cool.
- 7 Crush the avocados with the lime juice and coriander, and season to taste.
- 8 Generously spread the base of each taco with avocado.
- 9 Top with the roasted squash and the cooled, soused red onion.
- 10 Garnish the folded tacos with coriander leaves to serve.