Combine the first 6 ingredients in a saucepan; bring to a boil. Reduce heat; simmer 15 minutes. Discard ancho.
Melt margarine in a nonstick skillet coated with cooking spray over medium-high heat. Add chopped onion and garlic; sauté 5 minutes or until onion begins to brown. Add onion mixture to bean mixture. Stir in green onions.