Heat oil in 2-quart saucepan over medium heat. Add shrimp, onion and green pepper. Cook, stirring occasionally, until shrimp is no longer pink. Add Simply Potatoes, broth and Cajun seasoning. Bring to a boil. Reduce heat to low. Cook 20 to 25 minutes, stirring occasionally, until Simply Potatoes are tender.
In small bowl stir together flour and water until smooth. Slowly add flour mixture to soup. Stir in tomatoes. Cook until mixture is thickened and heated through.