Melt the butter in a large, shallow pan.
Add the carrots, tarragon and star anise.
Slowly cook for 10 mins until the carrots
are glazed and starting to soften. Pour
in the stock and bring to the boil, then
simmer everything for 20 mins until
cooked and the stock has reduced.
Pour in the cream, bring back to the
boil and simmer for 1 min more. Remove
from the heat, take out the star anise and
stir through the lemon juice. Season to
taste, then blitz with a hand blender until
as smooth as possible. The purée can
now be chilled or frozen, then gently
reheated before serving.