Cook pasta according to package directions, omitting salt and fat.
Sprinkle salmon evenly with salt, oregano, and black pepper.
Place on a broiler pan coated with cooking spray. Broil 10 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness.
Let stand 5 minutes; break into bite-sized pieces with 2 forks.
Combine pasta, salmon, spinach, and remaining ingredients in a medium bowl; toss well.