Use lightly smoked raw salmon fillets that have been hot smoked, not thinly sliced cold-smoked salmon. You could use ready- rolled bought pastry: just press the lemon zest into the pastry, fold and re-roll before lining the tin.
For the pastry
150g white spelt flour
85g cold butter, cut into cubes
1 small egg yolk
4tsp crème fraîche
grated zest of 1 small lemon
For the filling
50ml full fat milk
200ml crème fraîche
Large knob butter
200g prepared spinach (stalks and roots removed)
240g (2 small) lightly smoked salmon fillets, skinned and cut into 2 cm pieces
12cm x 35cm rectangular, loose-bottomed fluted tin
To make the pastry, put the flour and a pinch of salt into a processor, add the butter and pulse to a fine crumb. Mix the egg and crème fraîche together with the lemon zest and pour over the crumb mixture. Pulse to bring the mixture into a pliable ball. Tip onto cling film and squash a little, wrap and chill for 20 minutes. Preheat the oven to 220°C/ 425°F/Gas 7. Roll out the pastry to fit the tin and line with a sheet of scrunched-up baking paper. Fill with baking beans and bake blind for 20 minutes until the edges look like pale biscuit. Remove the baking beans and put the pastry back in the oven. Lower the heat to 180°C/350°F/Gas 4 and leave for 5 minutes to cook the base. Whisk the eggs, milk and crème fraîche together. Heat the butter in a large pan and add the spinach. Stir to wilt. When soft, drain well. Squeeze any moisture from the spinach and roughly chop. Add to the egg mixture. Season with nutmeg, sea salt and freshly ground black pepper. Pour the mixture into the cooked pastry case and push the pieces of salmon into the mixture, letting a few peek through the surface. Grind over a little more nutmeg and bake at 180°C/350°F/Gas 4 for 20 minutes until puffed, set and golden. Cool for 20 minutes before serving.