Coat medium skillet with cooking spray. Arrange tortilla strips in pan and coat with cooking spray. Cook over medium heat 5 minutes, flipping a few times until tortillas are golden and crispy. Remove to plate.
Coat large saucepan with cooking spray. Add onions, celery, tomatoes, basil, and cumin. Cook over medium heat 3 to 5 minutes.
Add vegetable broth and beans. Bring to boil. Lower heat to simmer 3 to 5 minutes.
Add cilantro, lime juice, and cayenne pepper. Season with salt, if desired.
When ready to serve, arrange tortilla strips in bowls (if using) and ladle soup on top.