Add the egg whites and 400ml water, and stir together with a wooden spoon to form a firm dough – add a little more water if needed.

Tip the dough onto a lightly floured surface and knead for 10 mins or until smooth.

Wrap in cling film and set aside to rest for 1 hr.

(You can also make the dough in a freestanding mixer with a dough hook attachment).

2)Heat oven to 160C/140C fan/gas 3 and line a baking tray with parchment.

Divide the dough into 4 even-sized pieces. On a lightly floured surface, roll each into a circle almost 1cm thick.

Place a lamb shank in the centre of each disc of dough and tuck 2 garlic cloves underneath.

Brush the edge of the dough with a little water, then gather it up and around the lamb shank, leaving the bone exposed.

Make sure all the meat is covered and the pastry is well sealed.

Transfer to the lined tray. Can be assembled 1 day ahead and chilled.

Put the lamb in the oven and bake for 3 hrs 30 mins, by which time the crust will have turned a dark brown.