Smoky fish, prawn & bacon pie

Method

• step 1

  Heat the oil in a large pan over a low-medium heat and cook the onion and fennel with a pinch of salt for 10-15 mins until softened and starting to caramelise.

• step 2

  Add the bacon and sizzle for 5 mins until starting to crisp. Splash in the vermouth and bubble for 1-2 mins until reduced. Stir in 50g butter to melt, then add the flour and quickly stir to make a paste. Pour in the milk, a splash at a time, whisking continuously until you have a smooth, silky sauce. Stir in the crème fraîche, mustard and parsley. Add a little lemon juice or zest, if you like.

• step 3

  Meanwhile, tip the potatoes into a large pan of water, bring to the boil and cook for 12-15 mins, until tender enough that a knife easily slides in. Drain well, then leave to steam-dry.

• step 4

  Remove the skin and any bones from the fish and cut into large chunks. Put in a baking dish (ours was 20 x 25cm) and scatter over the prawns. Mash the potatoes with the remaining 50g butter and a splash of milk. Stir in half the cheese and a pinch of cayenne pepper, and season well with salt.

• step 5

  Pour the sauce over the fish and gently mix to coat. Spoon or pipe the mash on top. Scatter over the remaining cheese and another pinch of cayenne. At this stage, the pie will keep chilled for up to a day.

• step 6

  Heat the oven to 200C/180C fan/gas 6. Cook for 35 mins (or 40 mins from chilled) until the topping is golden and crisp, and the sauce is piping hot.