This is a Mary Berry, absolutely foolproof.

1.5kg leg of Lamb (feeds 6)              750ml of water mixed with stock cube, I use Knorr rich beef

8 garlic cloves (sliced finely)          seasoning 

bunch fresh thyme                        1 heaped tbspn plain flour

2 red onions roughly chopped             1 heaped tbspn recurrant jelly 

1 tblspn olive oil

Preheat oven to 220, 200 fan, Gas 7. Pierce holes in lamb with sharp thin knife, stuff holes with garlic & thyme. 

Put onions in roasting tin, set a grill rack over & put lamb on rack, drizzle with oil & season well. Roast for 30-40 mins until brown, reduce oven to 140, 120 fan, Gas1. Pour stock around lamb & cover with foil, return to oven for 4 hours.

Remove & rest lamb, while you tackle the gravy. Mix flour with 3 tbsns of water to smooth paste, whisk into juices with jelly, stirring, bring to boil. Check the seasoning. Enjoy...#mint sauce.