step 1
Peel and slice the sweet potatoes into discs about a half centimetre thick.
step 2
Put the sweet potoatoes, onions, red pepper and cumin into an oven proof bowl and pour over the olive oil.
step 3
Roast in the oven at 200C for about 45 minutes until all the ingredients are soft.
step 4
Put the cooked vegetables into a blender and add the hot vegetable stock. Blend to a liquid and serve. Add more vegetable stock if you require a thinner consistency.