It's not just the Peruvians who love a fast fish cure; we Norwegians have a penchant for light ceviche-style cures that sing of summer and relaxed, no-cook evenings outdoors. Serve this with a chilled glass of German or Austrian Riesling as a starter.
Slice the halibut into 5mm thick pieces, as if you were slicing salmon for gravlaks.
Arrange in a large dish and in a separate bowl mix the riesling vinegar, fructose, zest of 1 lemon and season to taste. It should taste quite sweet and sharp, if there's not enough kick to the riesling vinegar then add the juice of the extra zested lemon.
Pour this over the halibut slices, and using your hands, gently mix the marinade into the fish, being careful not to break up the flesh of the fish.
Chill in the fridge for 20 minutes and serve either arranged on a long platter or on individual plates.
Sprinkle dried elderflowers on top of the cured halibut and serve with pickles.