Step 1

Preheat oven to 180°C. Heat half the oil in a large non-stick frying pan over high heat. Cook the lamb, in 3 batches, for 3-4 minutes or until browned. transfer to a 6.5cm-deep baking dish.

Step 2

Heat the remaining oil in the frying pan over medium heat. Cook the speck and mushroom for 4-5 minutes or until the mushroom is light golden. transfer to the dish. Cook the shallot in the frying pan, stirring for 2-3 minutes or until light golden. Stir in the garlic for 30 seconds or until aromatic. Stir in the flour for 30 seconds. Stir in the stock, tomato paste, Worcestershire sauce and bay leaves. Season. Bring to the boil. Pour over the lamb. Cover and bake for 1 1/2 hours. Uncover and bake for a further 45 minutes or until the sauce thickens slightly.

Step 3

Meanwhile, to make the cheesy potato crust, cook the potato in a large saucepan of boiling water for 10 minutes or until tender. drain and return to the pan. Mash until smooth. Season.

Step 4

Rub the butter into the flour in a large bowl until the mixture resembles fine breadcrumbs. Use your hands to rub in the potato and polenta. Stir in the milk and egg until combined.

Step 5

Arrange heaped dessertspoonfuls of potato mixture around the edge of the lamb mixture. Sprinkle over the mozzarella. Bake for 25-30 minutes or until golden.