Recipes: Roast pork belly with pommes boulangère

Gordon Ramsay's recipe is the perfect roast for entertaining foodie friends

2 pieces pork belly , about 16 x 12cm from the thin end (ask your butcher) , boned
couple handfuls rock salt
4 garlic cloves , boiled for 5 minutes, drained and mashed
2 large handfuls sage leaves, roughly chopped
2 large handfuls parsley , roughly chopped
4 lemons , zested

FOR THE POMMES BOULANGERE

4 tbsp olive oil
4 large onions , peeled and thinly sliced
24 thyme sprigs, leaves stripped
1,4kg potatoes , such as Maris Piper, Desirée, or King Edward
600ml-1 litre fresh chicken stock
100g butter , softened
Score the skin of the pork at 5mm intervals with a very sharp knife or craft knife (you can also ask the butcher to do this) and lay it skin-side down on a tray scattered with a thin layer of rock salt. Cover and put in the fridge for 24 hours - salting draws excess water out of the skin, firms up the flesh and, in my opinion, is the best way to get a really good, crisp crackling.
Jeat the oven to 190C/fan 170C/gas 5. For the pommes boulangère, heat the oil in a medium pan and fry the onions and thyme with some seasoning for 8-10 minutes, stirring occasionally, until the onions are soft and translucent. Peel and thinly slice the potatoes, preferably using a mandolin or slicing blade on a food processor. (If you don't own a processor with the right attachment, a mandolin is a very good investment.) Brush a wide ovenproof dish (or 2 smaller dishes) with a little oil and arrange a quarter of the sliced potatoes inside. Sprinkle with salt and pepper, then scatter over a third of the onions. Repeat, layering the potatoes and onion, seasoning well in between, and finish with a top layer of potatoes.
Bring the stock to the boil, then ladle it over the potatoes, letting it seep down until it reaches two-thirds up the sides of the potatoes and onions. Dot the top with some of the butter and bake for 45-50 minutes. If you are cooking more than 1 dish of potatoes, swap them around halfway through. Test whether they are done with the point of a sharp knife - it should slide through easily; keep cooking if you need to. Cover with foil and leave somewhere warm.
Meanwhile, brush any excess salt off the pork skin, put both pieces of the pork belly skin-side down on a chopping board and season well with pepper. Spread each with the mashed garlic, then scatter with the herbs and lemon zest. Carefully roll each piece, making the roll as tight as possible. tie every 2cm with kitchen string. Put join-side down, well apart, in a shallow roasting tin. Turn the oven up to 220C/fan 200C/gas 7. once it's hot, put the pork in and cook it for 30-40 minutes or until the crackling has crisped and frizzled, and the pork is just cooked through. swap the pieces over halfway through if one side seems to be cooking better than the other - ovens vary as to where their heat source is.
Once cooked, leave to rest before carving each roll into 6 fat slices. To plate up, mark the dish of potatoes into 12 squares and give each person a portion and a slice of pork