Preheat oven to 375 degrees. Lightly grease a large baking sheet.

Toss together Swiss cheese, ham and turkey; set aside.

Unfold puff pastry on a lightly floured surface; roll into a 15-by-10-inch rectangle. Spread evenly with honey mustard, leaving a 1/4-inch border; sprinkle with the cheese mixture.

Brush edges of puff pastry with some of the beaten egg. Starting at a short side, roll up like a jelly roll. Cut into 8 equal slices and place 2 inches apart on prepared baking sheet. Brush tops with remaining beaten egg.

Bake until golden brown and cheese is melted, 20 to 25 minutes. Cool briefly on wire rack. Sprinkle with powdered sugar; if desired.

Serve warm with preserves (or jam).