COAT both sides of fish with flour. Heat dressing in large skillet on medium-high heat. Add onions; cook and stir 5 min. or until crisp-tender. Add fish; cook 5 to 7 min. on each side or until fish flakes easily with fork.
MEANWHILE, blend cream cheese, red peppers, broth and garlic in blender until well blended. Pour into medium saucepan. Bring to boil on medium-high heat, stirring frequently; simmer on low 5 min., stirring occasionally.
PLACE fish on platter; top with cream cheese sauce and cilantro.