Saute onion and garlic in 2 tablespoons of olive oil until soft, stirring often. Add bean, water, bay leaves, and basil. Bring mixture to a boil, reduce to a simmmer, and cover. Continue cooking until beans are tender, about 2 hours, adding more liquid if necessary and stirring occasionally. Season with salt and pepper.
Cool soup, puree beans in a blender or food processor fitted with steel blade. Return pureed soup to pot; reheat over moderate heat, stirring often. Blend in remaining olive oil. Serve soup hot, garnished with chopped parsley and green onions. If soup is too thick, add water or chicken broth.
Nutrional Information: CAL: 293; CHO: 37g; PRO: 13g; FAT: 11g; SOD: 256; CHOL: 0g; Low-Sodium Diets: Omit Salt.