In a small bowl, combine mayonnaise, horseradish, and pepper, stirring well.
Using a 2¼-inch square cutter, cut squares from bread slices, discarding crusts. Top bread squares with pieces of smoked salmon and a dollop of mayonnaise mixture.
Serve immediately or cover with damp paper towels, place in a covered container, and refrigerate until serving time. Garnish with dill fronds, if desired.
Recipe by Victoria at https://victoriamag.com/piquant-salmon-canapes/