For the filling, peel and chop the onion. Heat the oil in a pan. Steam onion until transparent. Leave to cool. Mix with parsley, lemon peel and ground pork. Season well with salt and pepper.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Cut rind crosswise. Spread the filling into the meat pocket. Wrap roast with kitchen string. Rub all around with salt.
Place in a flat roasting pan or on a fat pan with the rind facing upwards. Peel shallots, cut larger ones in half. Spread around the roast. Add stock and wine. Roast in a hot oven for about 1 1⁄2 hours.
Add cream and peppercorns to the roaster. Mix 5 tbsp. water with 1 tsp. salt. Continue cooking for about 30 minutes, brushing the rind with the salted water about every 10 minutes. Switch on the oven grill.
Grill the crust for about 15 minutes until small bubbles form on it. Lift the roast out of the roaster, remove kitchen string. Cover with aluminium foil, let rest for about 10 minutes.
In the meantime, put the roast cream sauce in a pot, possibly skimming off fat. Bring to the boil and season to taste with salt if necessary. Thicken with sauce thickener as desired. Cut the roast into slices. Serve with sauce.
Ciabatta gnocchi, for example, taste good with it.