Melt butter in a large Dutch oven over medium-high heat; add onion and bell pepper, and saute 8 minutes or until onion is golden. Stir in garlic and ginger, and cook 1 minute. Add squash, next 7 ingredients, and 4 cups water. Bring to a boil, reduce heat to medium-low, and simmer 20 minutes or until vegetables are tender. Remove from heat, and let stand 30 minutes, stirring occasionally. Remove and discard bay leaves.