Preparation Peel beet, then cut into very thin slices (not paper-thin) with slicer. Cut slices into 1/8-inch-wide strips with a knife. Heat 1 inch oil in a 2- to 2 1/2-quart heavy saucepan until thermometer registers 320°F. Fry beet strips in 4 batches, stirring frequently, until frizzled, about 1 1/2 minutes per batch. (Strips will brighten slightly.) Transfer beets with a slotted spoon to paper towels to drain. (Beets will crisp as they cool.) Return oil to 320°F between batches. Pulse caraway seeds in grinder until finely ground. Transfer to a small bowl, then stir together with butter and salt. Mince together salmon and onion. Spread a thin layer of caraway butter on 1 side of each bread slice, then top with salmon mixture (about 1 heaping tablespoon per slice) and spread evenly. Cut slices in half, then cut each half crosswise into 3 pieces. (If using crackers, cut crosswise with a large sharp knife to make a total of 24 equal pieces.) Sprinkle with chives (if using) and frizzled beets. Cooks' note:Frizzled beets can be made 1 day ahead and cooled completely, uncovered, then kept in an airtight container at room temperature. Recrisp up to 2 hours ahead on a baking sheet in a 300°F oven 3 to 5 minutes. If beets are not crisp once cooled, return to oven briefly.
Preparation Peel beet, then cut into very thin slices (not paper-thin) with slicer. Cut slices into 1/8-inch-wide strips with a knife. Heat 1 inch oil in a 2- to 2 1/2-quart heavy saucepan until thermometer registers 320°F. Fry beet strips in 4 batches, stirring frequently, until frizzled, about 1 1/2 minutes per batch. (Strips will brighten slightly.) Transfer beets with a slotted spoon to paper towels to drain. (Beets will crisp as they cool.) Return oil to 320°F between batches. Pulse caraway seeds in grinder until finely ground. Transfer to a small bowl, then stir together with butter and salt. Mince together salmon and onion. Spread a thin layer of caraway butter on 1 side of each bread slice, then top with salmon mixture (about 1 heaping tablespoon per slice) and spread evenly. Cut slices in half, then cut each half crosswise into 3 pieces. (If using crackers, cut crosswise with a large sharp knife to make a total of 24 equal pieces.) Sprinkle with chives (if using) and frizzled beets. Cooks' note:Frizzled beets can be made 1 day ahead and cooled completely, uncovered, then kept in an airtight container at room temperature. Recrisp up to 2 hours ahead on a baking sheet in a 300°F oven 3 to 5 minutes. If beets are not crisp once cooled, return to oven briefly.