In a large nonstick pot, add olive oil, onions and garlic. Sauté for 2 minutes.
Add chopped tortillas, tomato paste, and all seasonings. Sauté for 2 minutes.
Stir in vegetable broth and tomatoes. Bring to a boil, turn down heat and simmer, uncovered, for 15 minutes.
Add beans, corn and fresh squeezed lemon or lime juice. Mix well. Cook 10 minutes more.
Top each with crushed tortilla chips and yogurt or sour cream, if desired.
This soup freezes great!