Smoked Ham, Leek and Mushroom Pie

1. To make the pastry, put the butter, egg and extra yolks into a food processor and whiz until pale; don't worry if the mixture looks curdled. Add the flour and salt and pulse until the mixture just begins to come together. Add 2 - 3 tbsp iced water, whiz for 1 second, then tip into a bowl and bring the dough together with your hands. Divide into two pieces, one slightly larger than the other. Wrap and chill for 30 minutes.

2. Roll out the smaller piece of pastry to a 11 x 9 inch rectangle on a sheet of greaseproof paper. Slide the dough on to a baking sheet. Prick all over with a fork and bake at 200°C (180°C fan oven) for 10 -15 minutes. Leave to cool.

3. To make the filling, melt the butter in a skillet, add the leeks and mushrooms and cook for about 10 minutes until soft; cool slightly. Stir in the cheeses and season well. Spread half of the mixture over the cooked pastry base, leaving a 1/2 inch border around the edges. Scatter the diced ham on top.

4. Mix the mustard with the fromage frais, season with salt and pepper to taste, then spread evenly over the ham. Top with the remaining leek and mushroom mixture. Lightly brush the pastry edges with water.

5. Roll out the larger piece of dough on a large sheet of greaseproof paper and loosen it from the paper with a palette knife. Position over the pie, then carefully slide the paper out leaving the pastry covering the filling. Press the edges together to seal, then trim and crimp, reserving the trimmings.

6. Roll out the reserved trimmings and cut out leaves or diamonds. Brush with a little water and arrange down the middle of the pie. Brush all over the surface of the pie with beaten egg, then bake for 35 minutes until the pastry is golden and crisp. Serve warm.