In large nonstick skillet, bring 3/4 cup water and broccoli to a boil. Reduce heat; cover and simmer 4 to 7 minutes or until broccoli is crisp-tender.
Meanwhile, place bread slices on ungreased cookie sheet. In small bowl, combine sour cream, horseradish and mustard; mix well. Spread over bread. Place turkey slices on bread.
Drain broccoli. Top each sandwich with 4 cooked broccoli spears, bell pepper strips and 3 strips of cheese.
Broil 3 to 4 inches from heat for 2 to 3 minutes or until cheese is melted.