Heat oil in a large pot over medium heat. Saute onion for 5 minutes. Add garlic and saute for 1 more minute, stirring constantly. Add roasted peppers, tomatoes, beans, and broth and bring to a boil. Reduce heat to medium and simmer, uncovered, for 15 minutes.
Remove from heat. Puree soup with an immersion blender (or let cool and use a blender to puree in batches). Serve warm with homemade croutons or grilled cheese sandwiches. Enjoy!