1. In a small bowl, dissolve 1 tsp wasabi powder in 1 tbsp warm water. Add 1/3 cup reduced-fat mayonnaise, 2 tbsp chopped parsley, 1 tbsp lemon juice; stir until smooth. Split open 8 sandwich thins (such as Arnold) and spread cut sides with wasabi mayonnaise. Place 2 slices roast beef (about 2 ounces) on each bottom half; top with alfalfa sprouts and other bread half.