• 675 g/1½ lb new potatoes
• 1 bunch spring onions
• generous bunch fresh dill
• 1 medium egg
• 4 rounded tablespoons crème fraîche
• 350 g/12 oz puff pastry
• a little milk
• salt
• black pepper

Scrub the potatoes but do not peel them. Boil or steam until just tender right through, then drain, slice across thinly and put on one side in a bowl until cold. Trim the spring onions and slice across finely, using as much of the green part as possible. Roughly chop the dill. When the potatoes are cold, mix the spring onions and dill gently into them. In another bowl, whisk the egg lightly, then stir in the crème fraîche. Season well with salt and plenty of black pepper. Using a wooden spoon so as not to break up the potatoes, stir the cream and egg into the potato mixture.

Preheat the oven to 220°C/425°F/gas mark 7. Butter a 24-25 cm/9½-10 in loose-based flan tin, either fluted or plain. Cut the pastry in half and form each half into a ball. Roll out one half thinly and use to line the flan tin. Spoon in the potato mixture. Roll out the remaining pastry into a circle big enough to top the pie and lay it on the filling, trimming round the edge. Press the edges lightly together to seal them, then roll out any trimmings to cut out decorations. Moisten the decorations underneath and arrange on top of the pie. Cut 2 holes in the pastry to allow steam to escape. Brush the pie lightly with a little milk and cook in the centre of the oven for 30-35 minutes, until a rich, golden brown. Before serving, press the pie up out of the flan rim and, using a wide spatula, ease it carefully off the base on to a flat serving plate.