Roll out the pastry to fit a 22.5 cm (9 inch) deep fluted flan dish. Press the edges up well and push the base well down. Prick the base with a fork and bake blind for 15 minutes in a preheated oven, 190°C/375°F/Gas Mark 5.

Poach the fish gently in the chicken stock for about 8 minutes, or until just tender. Drain the fish and flake it into a bowl, discarding any skin or bones.

Mix the chopped eggs, chives and cheese into the fish, and spread this mixture evenly into the part-baked pastry case.

Beat together the eggs and milk and season to taste. Pour over the fish mixture in the pastry case.

Bake for 25-30 minutes, or until the filling is set, at the same oven temperature as before.