1. Preheat broiler to high.
2. Place fillet on a foil-lined baking sheet; sprinkle fillet evenly with pepper. Broil 6 minutes or until desired degree of doneness. Cool 2 minutes; flake fillet.
3. Combine shallots and next 4 ingredients (through lemon juice) in a small bowl, stirring well. Place 2 toasted baguette slices on each of 6 small plates. Divide salmon evenly among baguette slices; top each crostini with 1 teaspoon crème fraîche mixture and 1 dill sprig.