1In 4 1/2- to 5-quart Dutch oven, heat oil over medium heat. Add onion, bell pepper and garlic; cook 5 to 6 minutes, stirring frequently, until onion is softened.
2Stir in remaining ingredients except polenta and green beans. Heat to boiling; reduce heat to medium-low. Cover; cook 35 to 40 minutes, stirring occasionally, until carrots are tender and stew is hot. Meanwhile, cook polenta as directed on package; keep warm.
3Stir frozen green beans into stew. Cover; cook 5 to 6 minutes, stirring occasionally, until beans are hot. To serve, spoon stew over polenta.