For the pork, using a very sharp knife (or a utility knife), score the skin of the pork really deeply in a criss-cross pattern with about a 1cm/½in gap between each cut. Boil your kettle, put the pork in a clean sink, skin-side up, and pour the boiling water over the skin of the pork – this scalds it and it will make sure the skin is crispy once it is roasted.
In a large bowl, mix the salt, garlic, paprika, vegetable oil and lemon pieces. Now, rub the mixture into the pork skin and flesh, leaving the lemon pieces sitting on top of the skin. Put the pork on a tray and leave it to marinate in the fridge for 12-24 hours.
Preheat the oven to 160C/140C Fan/Gas 3. Put the potatoes in a large roasting tin (the potatoes will act as a trivet). Lay the pork, skin-side up, on top of the potatoes and pour over any marinade left in the tray. Pour a mug of water into the bottom of the tray underneath the pork. Cover the pork with baking paper, then with foil and tuck the foil around the outside of the tin to seal. Roast for 4 hours.
Take the pork out of the oven and increase the oven temperature to 200C/180C Fan/Gas 6. Carefully remove the foil – the tin will be steaming. Put the pork back in the oven and roast for a further hour.
For the roast parsnips, heat the oil in a roasting tray until hot. Put the parsnips in a bowl and pour over boiling water to scald them. Drain the parsnips and pat dry, place in the hot oil and carefully toss so they are all covered. Roast for 45 minutes. Season with a little salt before serving.
Take the pork out of the oven and leave it to sit somewhere warm to rest for 30 minutes. While the pork is resting, make the mash and the salsa verde.
For the parsnip mash, put the parsnips, potatoes, garlic cloves in a saucepan and half cover with water. Add the milk and olive oil and season with salt and pepper. Cover with a lid and cook until completely overcooked, stirring constantly.
Drain well, transfer to a clean pan and keep warm, reserving the cooking liquid. Warm the cream and the butter. Put the cooked vegetables in a food processor with some of the cooking liquor and blend until smooth, add the cream and butter and blend more. If the mixture is too thick add a little more of the cooking liquid.
For the salsa verde, put the parsley, basil and garlic into a food processor and pulse until chunky. Add the remaining ingredients and pulse for 30 seconds or until the mixture has a roughly chopped texture – it should not be a paste.
When the pork has rested, lift it out of the tin and lay it skin-side down on a carving board. Score the underside of the pork so that you can see the ends of the bones. Pop them out using your thumb, then take the bones out by simply pulling at the sticking out ends – they should pull away from the flesh easily. Cut the pork in half lengthways, then cut each half into 5 or 6 slices. Flip each one over – it should be a lovely glistening slice of roasted deliciousness. The whole board goes to the table. Bowls of mash, bowls of salsa verde – go for it! Serve with the spuds that were cooked under the pork and the roast parsnips.