Ingredients

Step by step

1. Heat the oven to 160°C, fan 140°C, gas 3. Remove the parsley stalks and set aside, put the leaves in a food processor with the bread and blend until it makes fine crumbs.
2. Finely dice a quarter of the onion and slice the rest. Melt the butter in a pan and fry the diced onion for about 3-4 minutes, until softened. Remove from the heat and add the breadcrumb mixture to the pan, season well. Add the lemon zest, the juice from 1½ lemons and the egg; stir together.
3. Remove the string from the lamb and unroll, separate the 2 pieces of meat. Spread half the stuffing over one piece then put the other on top and cover with the remaining stuffing. Roll back up, tightly, then tie with string every 3cm along.
4. Put the sliced onion and parsley stalks in a small roasting tin and sit the lamb on top. Pour in 200ml hot water then cover loosely with foil. Cook in the oven for 2½ hours, removing the foil for the last 30 minutes and increasing the temperature to 180°C, fan 160°C, gas 6, to brown the outside.
5. Remove the lamb from the oven, put on a carving board or plate and cover with foil. To make the gravy, first skim the excess fat off the surface of the roasting juices and discard. Put the roasting tin on the hob, add the stock, stir well, then spoon 2-3 tablespoons of the liquid into a small bowl. Add the flour and mix to a thick paste. Bring the liquid in the roasting tin to the boil, then add the flour paste and stir until it comes to the boil again. Simmer for 1-2 minutes until thickened, add the juice from the remaining lemon half and season to taste. Slice the lamb and serve with the gravy.