Preheat your oven to 180 C / 160 Fan / Gas 4. Place the sweet potato cubes on an oven tray and cover with the olive oil, smoked paprika and chipotle flakes. Place in the centre of the oven to cook for 20 minutes. Meanwhile, start making the chilli.
Place a deep frying pan on a low-medium heat and add the oil. Once hot, add the onions and fry for 2-3 minutes. Add the garlic with the cumin, coriander, smoked paprika and chipotle and cook for a further 2 minutes. Add the chopped tomatoes, tomato puree and Quorn mince. Cook for 10 minutes. Meanwhile, remove the sweet potato from the oven. Add the black beans and roasted sweet potato to the chilli, then cook for a further 5 minutes before removing from the heat.
To make the salsa, combine all ingredients together in a bowl and set aside.
To make the burritos, take four large wholemeal tortilla wraps and heat them gently under a grill or in a dry frying pan. Once heated, lay them flat and divide the rice, coriander, chilli, salsa, lettuce, avocado, grated cheese and sour cream between them. To fold the burrito, pull one side over the centre of the burrito and firmly tuck your fingers to contain the filling into a roll. Tuck each side into the centre of the burrito and then roll the burrito until it is firmly wrapped and sit it on the seam. Cut in half to serve.