Method

Serves 4

Roll wet potatoes in crushed sea salt then put them on an oven rack in an oven preheated to 200C (fan bake). Turning potatoes occasionally, cook for 1 1/2 hours, or until they are very crunchy. To save making a mess in the oven, put a sheet of tin foil under the oven rack to catch the falling flakes of salt.

Remove potatoes from oven and immediately cut each one in half (be careful of the steam). Scoop out the flesh and mash it in a china bowl (china retains heat) with a potato masher.

Add butter, hot milk and 1/2 tsp of salt. Keep potato hot in the bowl covered with a china plate until mushrooms are ready.