Twice-baked potatoes with blue cheese and hazelnut

Bake two-thirds of the potatoes in the oven for about an hour; meanwhile boil the remaining potatoes and peel them.

Halve the baked potatoes and scoop out the flesh from the center with a melon baller.

Pass all the potato flesh through a food mill, or mash with a fork; the food mill gives a fluffy, super smooth result. Do not over-beat, which makes them gummy.

Season the potatoes with salt and pepper.

Melt together butter, sour cream and roquefort, stirring; do not boil, keep it lukewarm.

Toast the hazelnut meal and set aside.

Mix the mashed potatoes with the cheese mixture and toasted hazelnut meal, starting with the paddle attachment and finishing with the whisk; readjust the seasoning.

Pipe the filling into the potato shells with a large open pastry tip, shower with grated parmigiano reggiano, and bake until golden brown.