This dish comes from Nigel Hawarth of The Three Fishes and Northcote Manor in Lancashire. He served it up at one of his annual food festivals, where he invites chefs from around Britain and further afield to cook for the evening. It can also be made with sea trout.
1 salmon fillet (with skin), about 750g-1kg, trimmed
80g black treacle
1tsp fennel seeds, crushed
Grated zest of 1 lemon
50g sea salt
1tbsp English mustard
2tsp coarsely ground black pepper
Lay the salmon fillet skin-side down on a sheet of clingfilm. Lightly warm the treacle in a bowl over a pan of simmering water, just until it is runny. Mix the fennel seeds, lemon zest, salt, mustard, pepper and treacle together. Spread evenly over the salmon and wrap well in more clingfilm. Place on a tray (still skin-side down) and leave at room temperature for 1 hour, then refrigerate for 48 hours.
When ready to serve, remove the clingfilm and scrape away any excess liquid and marinade from the salmon. Pat dry with kitchen paper.
Cut at a 90-degree angle to the skin into even slices, about 3mm thick. Serve with pickled cucumber or just some good bread and a leafy salad.