1 salmon fillet (with skin), about 750-1kg/1lb 10oz-2lb 4oz, trimmed
80g/3oz black treacle
1 tsp fennel seeds, crushed
grated zest 1 lemon
50g/2oz sea salt
1 tbsp English mustard
2 tsp coarsely ground black pepper
2 medium cucumbers
2 tbsp good-quality white wine vinegar
grated zest 2 lemons
4 tbsp rapeseed oil
good pinch salt
4 tbsp chopped dill
Lay the salmon fillet skin-side down on a sheet of cling film. Warm the treacle in a bowl over a pan of simmering water until it is just runny. Mix the fennel seeds, lemon zest, salt, mustard, pepper and treacle together. Spread evenly over the salmon and wrap well in more cling film.
Place on a tray, still skin-side down, and leave at room temperature for 1 hr, then refrigerate for 48 hrs. For the pickled cucumber, halve the cucumbers lengthways and scoop out the seeds, then cut the flesh into 3mm slices and place in a bowl. Add the wine vinegar, lemon zest,
rapeseed oil, salt and dill and toss to mix. Cover and leave to stand for about 45 mins before serving.
When ready to serve, remove the cling film and scrape away any excess liquid and marinade from the salmon. Pat dry with kitchen paper. Cut the salmon at a 90-degree angle to the skin into even slices, about 3mm thick. Serve with pickled cucumber or pickled samphire, or just some good bread and a leafy salad.