Melt the butter in a large saucepan
Add the 500g carrots (thinly sliced), 1 onion (thinly sliced), 1 potato (thinly sliced) and 1 garlic clove (crushed)
Cover with a lid and leave over a low heat for 12 minutes (until veg has softened)
Pour in 1 litre veg stock
Bring to the boil and simmer for 20-30 minutes or until the vegetables are very soft
Take off the heat and leave to cool
Transfer the veg into a blender and blend until smooth
Pour back into the pan
Squeeze in the juice on one orange and 2 tbsp of mint (finely chopped)
Serve with a warm bun