MELT butter in medium saucepan over medium heat. Add bell pepper, onion and cumin; cook for 3 to 4 minutes or until tender. Stir in broth, salsa and corn. Bring to a boil. Reduce heat to low; cook for 5 minutes.
HEAT vegetable oil in medium skillet over medium-high heat. Add tortilla strips; cook for 3 to 4 minutes or until crisp.
SERVE in soup bowls. Top with tortilla strips, cheese and a dollop of sour cream.