1In 3-quart saucepan, heat oil over medium heat until hot. Cook onion and garlic in oil about 5 minutes, stirring occasionally, until tender.
2Add broth, roasted peppers, sugar, salt and pepper. Cook uncovered 10 minutes over medium heat, stirring occasionally. Remove from heat.
3In blender, place half the mixture with half the basil. Cover; puree until smooth. Repeat. Return to saucepan; stir in yogurt, and heat over low heat just until hot (do not boil). Garnish with additional fresh basil and fresh ground black pepper, if desired.