Preheat the oven to 200°C.

Prick the potatoes all over with a sharp knife. Wrap the whole garlic bulb in foil. Put the potatoes into a roasting tin, season and bake for 1 hour until completely tender, adding the wrapped garlic to the tin after 20 minutes. After 40 minutes it should be super soft.

Meanwhile, halve and thinly slice the leeks. Using one hand, hold each cavolo nero stalk and use the other to strip the leaves away from the stalk, then finely chop the stalks.

Get a large frying pan over a medium heat. Add 2 tsp of the olive oil, the sliced leeks and chopped cavolo nero stalks along with 3 tbsp of water. Cook until the water has evaporated and the leeks are collapsed and soft. Add the cavolo nero leaves and peas and cook for a few minutes more until everything is tender. Stir through 2 tsp of the mustard, then scrape into a large bowl and set aside.

Once the garlic is cooked, squeeze out onto a chopping board, mash with a fork then stir through the greens.

Cut the baked potatoes in half and leave to cool a little, then spoon the potato centre into the greens and mix together. Increase the oven temperature to 220°C.

Put the potato skins back into the roasting tin, drizzle with a teaspoon of olive oil and bake for 5 minutes so that they crisp up slightly.

Meanwhile, grate the cheese. Season the filling to taste and then load into the potato skins and sprinkle over the cheese. Return to the oven for 10 minutes until bubbling and golden.

Salsa verde time. Chop the cornichons and parsley (stalks and all) and mix together with the remaining teaspoon of mustard, 2 tbsp of olive oil and the red wine vinegar. Season to taste – you want it punchy. Serve the cornichon salsa verde with the loaded potato skins and a big green salad, if you like.