Place the salt, sugar, coriander seeds, juniper berries, peppercorns, lemon, 50g dill and gin into a food processor and blitz.
Spread over both sides of the trout until completely covered, then wrap in cling film, place on a tray (juices may escape) and refrigerate for 24 hours.
Unwrap the trout and gently rinse off the curing paste under slow running cold water.
Pat dry with kitchen towel.
Chop the remaining dill.
Spread the Dijon mustard thinly over the trout and coat well in the dill.
Wrap it tightly in cling film and refrigerate until needed.
To make the sauce
Mix together the mustard, honey and cider vinegar in a bowl.
Whisk in the olive oil then add the dill, lemon zest and juice and season with salt to taste.
Serve with slices of thinly carved trout gravadlax.
