For gravlaks
1 (1 1/4-lb) center-cut piece arctic char fillet with skin, pin bones removed
1/2 cup sugar
1/4 cup kosher salt
1 tablespoon coarsely ground black pepper
3 cups coarsely chopped fresh dill (from 2 large bunches)
For cucumber jelly
3 seedless cucumbers (usually plastic-wrapped; 3 lb total)
3/4 teaspoon table salt
2 teaspoons unflavored gelatin (from 1 envelope)
1 tablespoon distilled white vinegar
1 tablespoon tiny fresh dill fronds
Accompaniment: thin Scandinavian crispbread such as Kavli
Make gravlaks:
Pat fish dry, then transfer, skin side up, to a large sheet of plastic wrap.
Stir together sugar, salt, and pepper, then rub 3 tablespoons of mixture onto skin of fish.
Turn fish over and thickly coat with remaining sugar mixture, then pack dill on top.
Wrap fish tightly in 2 or 3 layers of plastic wrap (to prevent leakage;
salt mixture will liquefy as fish cures) and transfer to a large shallow baking pan.
Put another baking pan or a cutting board on top of fish and weight down with 3 or 4 full cans (about 3 lb total).
Let fish cure, chilled, turning wrapped fillet over roughly every 12 hours
and then replacing weight, for 36 hours total.
Make jelly while fish is curing:
Peel cucumbers, making sure to remove all green (for a clearer jelly),
then halve lengthwise and core. Coarsely chop cucumbers and purée
in a food processor until smooth, then drain in a large fine-mesh sieve set over a bowl,
pressing hard on solids to extract 2 cups liquid. Discard solids.
Stir together salt and 1/2 cup cucumber liquid in a small saucepan and sprinkle with gelatin.
Let stand 1 minute to soften, then heat over moderate heat, stirring,
just until gelatin is dissolved, about 2 minutes. Cool mixture to room temperature,
then stir into remaining 1 1/2 cups cucumber liquid along with vinegar.
Pour mixture into an 8-inch square glass baking dish and sprinkle with dill fronds,
pressing gently to submerge. Chill, covered, until set, at least 8 hours.
To serve:
Unwrap gravlaks, discarding liquid, and gently scrape off dill.
Transfer gravlaks, skin side down, to a cutting board.
Holding a very sharp long thin-bladed knife at a 30-degree angle, cut gravlaks across
the grain into very thin slices, being careful not to cut through skin. Discard skin.
Cut jelly into 6 pieces and divide among 6 plates with a metal spatula.
Serve with several slices of gravlaks.
Cooks' notes:
• Cured gravlaks can be drained, scraped, and wrapped in clean plastic wrap,
then chilled up to 5 days.
• Jelly can be chilled up to 4 days.
Makes 6 first-course servings.