In a bowl, combine all the ingredients for the sweet potato and mix well. Transfer to a large baking sheet.
In the same bowl, combine the peppers, onions and flavourings and mix well. Transfer to the same baking sheet. (Keep the peppers and onions to one side, sweet potato to the other.)
Place the vegetables in the oven and allow to roast for 30-45 minutes until they are cooked through, soft and caramelised.
To make the burrito bowls, place rice in the bottom of a serving bowl then top with the vegetables, avocado and sour cream.
Finish with chillies (optional) and coriander then serve.