Melt 1/4 cup butter in a medium saucepan over medium-high heat; add onion and next 3 ingredients, and saute 5 minutes or until onion and bell pepper are tender. Stir in tomatoes, next 3 ingredients, and, if desired, basil. Bring to a boil; reduce heat, and simmer 3 minutes.
Combine flour, baking powder, and salt in a medium bowl; cut in 1 tablespoon butter with a pastry blender until mixture is crumbly. Add egg, milk, and parsley, stirring until dry ingredients are moistened. Drop dough by tablespoonfuls into simmering tomato mixture.
Cover and cook over medium-low heat 20 minutes. Remove and discard bay leaf. Serve immediately.