Cook onions and carrots in 1 1/2 Tbsp butter until tender, meanwhile, make cream sauce by melting 1 1/2 Tbsp butter in heavy sauce pan.
Stir in flour. Gradually add milk, stirring constantly until sauce thickens. Stir in salt and parsley. Combine beans, vegetables and cream sauce in a casserole. Top with cheese. Cover and bake for 45 minutes at 300F.
Nutrition Info Per Serving: Calories 392 Total Fat 14 g Cholesterol 36 mg Sodium 525 mg Potassium 936 mg Total Carbohydrate 49 g Dietary Fiber 14 g Sugars 6 g Protein 20 g