Method

1. Heat oven to 200C/180C/gas 6. Prick the potatoes all over with a fork, rub with oil and bake directly on the oven shelf for 1 hr 20 mins. Once cooked, leave for 10-15 mins or until cool enough to handle, then slice in half, scoop out the potato flesh and push it through a potato ricer or colander. Cover until needed. (I like to keep the potato skins for another day and stuff them with leftover mash, softened leeks and cheese, and bake until golden and bubbling.)

2. Mix the herb butter ingredients together, spread out into a rough log shape on a piece of baking parchment, roll up and twist the ends tightly so it resembles a cracker. Put in the freezer for 10-15 mins to firm up.

3. Heat the milk and butter for the mash in a saucepan until the butter has melted and the mixture starts to simmer. Pour this over the potato flesh, mash it and sprinkle over the nutmeg and some seasoning. Keep warm or reheat when serving.

4. Heat a large, non-stick pan over a medium-high heat. Season the flour with pepper, then use it to very lightly dust the liver. Pour the oil into the hot pan, season the liver well with sea salt, then fry for no more than 2 mins each side. Transfer to a plate and cover with foil.

5. Turn down the heat, but while the oil’s still hot, add the pickled onions. As the onions start to caramelise, put them on the plate with the liver. Add the garlic to the pan, which by now should be sufficiently cooled enough not to burn it. Add a little oil to the pan if it looks dry. Once the garlic is starting to soften but not coloured at all, add 4-5 thin slices of the parsley butter and some of the resting juices from the liver plate. Turn off the heat and allow the butter to melt but not colour.

6. Heap your mash onto two plates, top with the liver, sliced if you like, and the onions. Then generously drizzle over the herb butter. Serve with a crisp, mustardy salad.