Heat the butter and oil in a saucepan. Add chopped carrots and onion and sweat over a low to medium heat, until soft (this will take about ten minutes).
Add the flour and cook for 1 minute. Remove from the heat gradually stirring in the stock. Bring to the boil.
Add the orange rind and juice. Season with salt and pepper and simmer for a further 25 minutes and blitz until smooth.
To serve, drizzle with cream and dot with parsley leaves.