Cut 1/2-inch off tops of rolls. From bottom piece, remove inside crumb, leaving 1/2? border on bottom and sides. Place rolls and tops on baking sheet in preheated 400° oven approximately 6 minutes. Place sauce mix in medium saucepan. Stir in cornstarch, slowly stir in water and blend until smooth over medium heat, stirring constantly, until mixture boils. Remove from heat and stir in lemon juice. Stir in asparagus, ham and mushrooms. Gently fold in sliced hard-cooked eggs. Cook over low heat just until heated through, approximately 2 to 3 minutes. Place rolls on serving plates and fill each with about 1 cup of mixture.