MELT butter in 3-qt. saucepan on medium heat. Add green peppers, carrots, potatoes and onions; cook 20 min. or until vegetables are tender, stirring occasionally.
ADD flour; cook and stir 1 min. Gradually add broth, stirring until well blended after each addition. Bring to boil, stirring constantly. Reduce heat to medium.
ADD cheese; stir until completely melted. Gradually add milk, stirring until well blended after each addition. Stir in peas. Cook until heated through, stirring occasionally. Season with the white pepper.