Salmon & herby potato coulibiacs

Heat oven to 180C/160C fan/gas 4. Par-boil the potato slices for 2-3 mins. Drain and set aside in a large bowl.

Gently fry the onion in the oil for 10 mins until lightly golden. Cool slightly, then stir in the cream, crème fraîche, herbs, zest and plenty of seasoning. Pour over the potatoes and mix very gently.

Roll out one pack of pastry on a lightly floured surface to a 35 x 35cm, then lay on a large baking sheet. Pack ¼ of the potato mixture down one side of the pastry, leaving a 5cm border. Arrange ½ of the salmon on top to cover the potato. Cover the salmon with ¼ of the potato. Brush the pastry all the way round with beaten egg and fold over the pastry. Trim the edges and crimp with your fingers, or seal with a fork. Make decorative fish for the top, if you like.