Cut tortillas into eighths. Coat nonstick cookie sheet with vegetable spray. Toast tortillas on cookie sheet at 400° F for 10 minutes or until crisp. Sauté vegetables in vegetable oil for 2 or 3 minutes. Add 2 cups water, bouillon, oregano, cornstarch paste, cilantro, salsa and pinto beans and let simmer for 5 minutes. Ladle soup into 4 shallow bowls. Distribute toasted tortilla pieces equally between the bowls. Top each bowl with 1/4 cup shredded cheese and a pinch of thyme.