For the pastry
- 200 g plain flour
- A pinch of salt
- 100 g cold, unsalted butter, cut into small cubes
- 1 egg, separated
- 50 ml cold milk
For the filling
- 350 g smoked mackerel or pollack fillet
- 200 ml whole milk
- 140 g Dulse, well rinsed and finely shredded
- A knob of unsalted butter
- 2 onions, peeled and finely sliced
- 200 ml double cream
- 2 eggs
- 2 egg yolks
- Freshly ground black pepper
How to Make It
- To make the pastry, put the flour, salt and butter into a food processor and pulse until the mixture has the consistency of breadcrumbs. Add the egg yolk and then, with the motor running, trickle in the milk through the funnel, stopping as soon as the dough comes together; don’t overprocess. Tip the dough on to a lightly floured surface and knead gently to make a smooth ball. Wrap in cling film and chill for half an hour.
- Preheat the oven to 170°C/Gas Mark 3. Roll out the pastry on a lightly floured surface and use to line a 28 cm loose-bottomed tart tin, allowing the excess pastry to overhang the rim of the tin. Prick the base in several places with a fork, line with a sheet of greaseproof paper and fill with baking beans or rice. Bake for 15 minutes, then remove the paper and beans and return to the oven for 10 minutes until the base looks dry and cooked through. Lightly beat the egg white and brush all over the pastry to seal, then bake for a further 5 minutes until golden. Trim off the excess pastry from the edge with a small, sharp knife.
- For the filling, flake the fish from its skin, removing any bones. Tip the flaked fish into a bowl and set aside. Put the skin into a pan with the milk and bring to a bare simmer. Take off the heat and leave to infuse while you get on with everything else.
- Put the Dulse into a pan and cover with about 3 cm cold water. Bring to the boil and simmer for about 7 minutes until tender. Drain well.
- Heat the butter in a frying pan over a medium-low heat, add the onions and fry very gently until soft and just beginning to turn golden, about 15 minutes. Gently stir in the Dulse and flaked fish, then tip the mixture into the tart case.
- Strain the infused milk into a bowl and add the cream, eggs and egg yolks. Whisk together, then season with pepper and pour over the filling. Bake at 170°C/Gas Mark 3 for 40 minutes until lightly set and browned. Serve warm or cold.