Heat again the potatoe purée on a warm
hob and stir it with a wooden spatula in order to dry it during 2 to 3 minutes, then add the butter
in small cubes, then the boiling and seasoned milk
so that you get the right consistency. Fine tune the seasoning, then add, out of the hob, the truffle
cut in thin sticks ('julienne' cut) and keep it aside.