Dice the onion and pepper relatively small and finely chop the garlic. Warm the grill and heat the water or stock.

Wash then pierce the sweet potatoes a few times. Wrap the sweet potatoes in kitchen roll and microwave on high for around 2-3minutes, turn over, then another 2-3minutes (time depends on size of potato and microwave power). They should be soft when squeezed once cooked.

Warm 1tbsp of oil in a small pan over a medium heat and gently fry the onion, pepper and garlic until the onion is soft and starting to brown. Remove from the heat and set aside.

Meanwhile, put the quinoa and water/stock in a pan, bring to the boil and cook until all the water has been absorbed and the quinoa has slight 'tails', around 10 minutes.

While it's cooking, slice the sweet potato fairly thickly, around ½in/1.5cm, with skin on and peel then slice the plantain. Grill both on the barbecue for around 3-5 minutes each side until you have a few blackened marks on all the slices. If you don't have a barbecue, you can also do this on a grill pan.

Once the quinoa has cooked, add the onion mixture along with the remaining 1tbsp of oil, cumin, orange juice and juice of ½ lime. Mix well.

Peel and dice the mango and avocado then mix with the juice of a lime and the chopped cilantro.

Put some of the quinoa in the bottom of four bowls then top with the grilled sweet potato (you can peel before serving if you like, it just holds together better on the grill with skin on), plantain and some salsa.