Heat oven to 350°F. Spray cookie sheet with cooking spray.
Place rolls on microwavable plate. Microwave uncovered on High 10 seconds. Turn over, and microwave 10 seconds longer. Press and stretch each roll into 5-inch round.
Spoon about 1 1/2 teaspoons dressing on each round to within 1/2 inch of edge. On half of each round, place half of corned beef (folding if necessary), sauerkraut and Swiss cheese. Fold dough over filling; press edges with fork to seal. Brush with egg; sprinkle with sesame seed.
Bake 15 to 20 minutes or until golden brown.