Toss the lamb in the flour seasoned with salt and pepper. Shake away the excess flour; reserve remaining flour. Heat 1 tablespoon of the oil in a large frying pan over a medium-high heat. Add lamb, cook until browned all over. Transfer lamb to a slow cooker.

Heat the remaining oil in the same pan over medium heat. Add the carrot, celery, onion and garlic; cook, stirring, for about 5 minutes or until the onion is soft but not browned. Add tomato paste; cook, stirring, for a further 1 minute.

Stir in wine; bring to the boil. Blend reserved flour with a little of the stock in a small bowl until smooth. Add flour mixture, remaining stock and herbs to pan; bring to the boil. Add to slow cooker. Make sure all the meat is submerged in the liquid – any meat poking out the top will be tough and dry.

Put the lid on and cook on low for 6-8 hours (or high for 3-4 hours). The meat will be tender and falling off the bone.

Remove the lamb and vegetables from the sauce with a slotted spoon; cover to keep warm. Discard the bay leaves. Pour the sauce into a medium saucepan. Boil, stirring, for about 15 minutes or until the sauce is thickened.

Using two forks, shred the lamb and remove and discard the bones. Add the lamb and vegetables to the pan with the thickened sauce. The mixture should be thick and rich-flavoured, and not too wet. Season to taste; cool.

Meanwhile, preheat the oven to 180°C (160°C fan-forced). Divide pastry into 8 pieces. Roll each piece on lightly floured surface until large enough to line 8 individual metal pie dishes. Ease the pastry into dishes; trim edges, leaving a small overhang of pastry. Or, cut the shortcrust pastry sheets in half diagonally and line 8 individual metal pie dishes with the pastry. Trim the edges, leaving a small overhang of pastry.

Line the pastry with baking paper and fill with pastry weights or rice. Place pie dishes on an oven tray. Bake for about 15 minutes or until golden brown. Remove the paper and weights. Cool on a wire rack. Increase the oven temperature to 220°C (200°C fan-forced).

Divide the lamb mixture between pastry cases. Cut rounds from puff pastry to fit over the tops of the pies. Brush the edges of the pie cases with a little egg and place the puff pastry on top; use a fork to seal the edges. If you like, use some of the pastry scraps to make lamb shapes to go on top.

Brush the pie tops with egg; bake for about 25 minutes or until puffed and golden.