Prep Time: 15 minutes
Cook Time: 4 minutes
Place roll halves, cut-side up, on broiler pan. Preheat broiler. Broil 5 inches from heat 1 minute or until toasted. Spread 1 teaspoon butter and 1/4 teaspoon mustard on each toasted roll half. Top each with 1 slice cheese. Divide crab meat and asparagus spears evenly among roll halves.
Broil 1 to 2 minutes. Place 1 slice cheese on top of each; sprinkle with paprika. Broil 1 minute more or until cheese is melted and sandwich is hot and bubbly.