Heat oven to 350°F.
If using crescent rolls: Unroll dough; separate into 2 long rectangles. Press each into 12x4-inch rectangle, firmly pressing perforations to seal. If using dough sheet: Unroll dough; cut into 2 long rectangles. Press each into 12x4-inch rectangle.
In small bowl, mix mustard and honey; spread over each rectangle. Top each with salmon, onion and chopped dill. Starting with one short side, roll up each rectangle; press edge to seal. With serrated knife, cut each roll into 8 slices; place cut side down on ungreased cookie sheet.
Bake 13 to 17 minutes or until edges are deep golden brown. Immediately remove from cookie sheet. Garnish each with dill weed sprig. Serve warm.