- Remove any pin/large bones with tweezers.
- Line a deep china roasting dish with clingfilm (avoid metal as the acidity may react with it) and place the fish on it, skin side down.
- Crush the juniper and peppercorns in a pestle and mortar. Mix together with the remaining ingredients. Spread the mixture over the salmon, gently pressing into the flesh.
- Wrap the fish tight in the clingfilm and repeat with another layer all around it.
- Place a plate or baking sheet on top and weigh it down with jars or cans. Leave in the fridge for at least 36 hours, ideally up to 72.
- Unwrap the fish and scrape off the marinade.
- The salmon is now ready to serve – slice at an angle so you can see both the deep red colour and the delicate orangey/pink flesh. It will keep for 5 days in the fridge.
- Serve with quick-pickled vegetables and horseradish sauce.
Slice the vegetables thinly. Place in a colander and sprinkle with salt. Cover with a plate and set aside for 20 minutes. Mix together the other ingredients. Remove the plate and gently squeeze the vegetables removing excess moisture by patting dry with kitchen paper. Toss with vinegar mix. Leave for 10/20 minutes and serve.