Heat margarine over medium heat in a large stock pot.
Add onions, bell peppers, garlic, ginger, and red pepper flakes. Sauté uncovered for 3 minutes over medium heat until tender and translucent. Stir frequently.
Add spinach in batches (1 lb per batch). Add additional batch once current batch begins to wilt.
Add tomato paste before adding the last batch of spinach. Add salt. Stir well. Heat uncovered for an additional 5 minutes or more until spinach reduces.
Critical Control Point: Heat to 165 °F or higher for at least 15 seconds.
Transfer to a steam table pan (12″ x 20″ x 2½”) lightly coated with pan-release spray.
For 50 servings, use 2 pans.
For 100 servings, use 4 pans.
Critical Control Point: Hold for hot service at 135 °F or higher.
