Roll out the pastry and use half to line a large pie plate.
2. Top and tail the leeks and wash thoroughly.
3. Slice into 2.5 cm (1 in) lengths and cook in boiling salted water for 5 minutes.
4. Drain well and allow to cool.
5. Arrange the leeks in the pie, make four hollows in the leeks with the back of a spoon, then break an egg into each depression. Season well.
6. Mix the butter with 1 tablespoon of the milk and pour over the leeks.
7. Put on the pastry lid, making a few vents, glaze with the rest of the milk and bake at 200°C, 400°F, mark 6 for 35 minutes until the pastry is golden and the filling cooked through.