Wash and peel the carrots and chop into thin rounds. Pop the carrots into your pot and add cold water to about 1 inch above the level of the carrots. Add the butter, cover and turn the heat to high and leave to boil for about 20 minutes.
After 20 minutes check your carrots, if soft and liquid is now below the level of the carrots take off the heat and drain using a colander and the jug to collect the liquid. If not leave for another 5 minutes to reduce the liquid further with the lid off.
Add the carrots to the blender with half of the liquid from the carrots and blend. If your puree is not liquid enough add the remaining liquid and pulse a few times. Serve with your desired main and enjoy!