In her introduction to this recipe, Sophie Grigson describes koulibiac as ‘about as sophisticated as a fish pie can get’. It’s certainly a show-stopping party piece, and really not very hard to make. It can be served hot or cold, accompanied by hollandaise sauce or mayonnaise – it does need some kind of sauce in spite of the addition of melted butter at the end. To cook the salmon, wrap in foil, moistened with a splash of white wine or lemon juice and a couple of knobs of butter; season, pile in some sprigs of parsley and dill, then bake at 180 (fan) for 20-25 minutes. To hard-boil the eggs, place in cold water, bring up to a boil and cook for 8 minutes from the point when the water begins to roll.
500 puff pastry
1 egg yolk, mixed with a dash of milk
For the filling
15g porcini mushrooms
60g basmati rice
¼ tsp ground turmeric
1 onion, chopped
175g button or chestnut mushrooms, chopped
600g cooked salmon, flaked
2 tbsp chopped parsley
2 tbsp chopped dill
2 hard-boiled eggs, shelled and chopped
salt and pepper
Start with the filling. Soak the porcini in hot water for 30 minutes. Pick out the pieces and chop finely. Strain the soaking liquid through a very fine sieve to remove the grit and save it for future use. (Stick it in the freezer, in a jar, to use in a sauce / stew / risotto.)
Cook the rice with the turmeric in lightly salted water until al dente (approx 11 minutes), then drain thoroughly. Soften the onion in the butter without browning, add the mushrooms and the porcini and continue cooking until all the water released by the mushrooms has evaporated. Mix with the rice, salmon, herbs and hard-boiled eggs. Season generously with salt and pepper.
Roll out the pastry on a lightly floured surface to form a rectangle slightly bigger than 30 x 40cm. Trim the edges to even them up and give you some strips for decoration. Transfer the pastry to a lightly greased baking sheet (line with baking parchment too if you have some). Mound the filling down the centre of the pastry, shaping and squeezing it to form a fat sausage. Brush round the edge with egg wash. Lift the sides of the pastry up round the filling and press together to join. Seal the ends too, using more egg wash and folding the joints towards the long, central seam. Gingerly roll the koulibiac over, so that the joins are tucked away underneath. Decorate with pretty pastry shapes (try to control your baser urges, boys, at this juncture). Rest for half an hour before baking. Preheat the oven to 200C / 180 fan.
Brush the pastry with egg wash and make four slashes across the top, so that steam can escape. Bake for 35-40 minutes, until golden brown. Remove from the oven and pour the melted butter into the koulibiac, through the slits in the top.