In a large saucepan heat 1 tablespoon oil over medium heat. Add onion and garlic; cook for 3 to 4 minutes or until onion is tender, stirring occasionally. Stir in broth, roasted peppers, potato, oregano, and salt. Bring to boiling; reduce heat. Simmer, covered, for 15 minutes. Remove from heat.
Using a hand-held immersion blender, blend soup until nearly smooth. (Or let soup cool slightly. Transfer soup, one-third at a time, to a food processor or blender. Cover and process or blend until smooth. Return soup to saucepan; heat through).
In a small bowl combine pesto and 1 tablespoon oil. To serve, ladle soup into bowls. Drizzle with pesto mixture.