Prepare the hearts by drying them and filling each one with the stuffing mix.
Use a skewer or sew with string the flaps at the top of each heart to hold in the stuffing.
Heat the lamb fat in a small baking tin then add each heart
Baste well, and bake in a moderate oven, 180°C, Gas 4, for 45 minutes
Baste them during cooking 2-3 times.
When cooked, transfer them to a warmed serving dish, remove the skewers or string and keep them hot
Drain away the fat from the tin and keep any meat juices.
In a small bowl blend some of the stock with the flour to make a paste.
Mix the paste into the pan juices, and stir in the remaining stock.
Heat until it simmers, stirring all the time until it thickens.
Season well with salt and pepper.
Pour a little of this gravy round the hearts and serve the rest in a warmed sauceboat.
Accompany with a seasonal selection of Organic Vegetables.