Heat oven to 375°F. In Dutch oven or 4-quart saucepan, heat oil over medium heat until hot. Add onions and garlic; cook and stir 5 to 7 minutes or until onions are tender.
Stir in sweet potatoes, broth, cumin, oregano, chili powder and ground red pepper. Bring to a boil. Reduce heat to low; cover and simmer 20 minutes or until sweet potatoes are tender.
Meanwhile, arrange tortilla strips in single layer on ungreased cookie sheet. Lightly spray strips with nonstick cooking spray. Bake at 375°F. for 8 to 12 minutes or until light brown and crisp. Cool on paper towels. Set aside.
Carefully transfer 2 1/2 cups hot sweet potato mixture to food processor bowl with metal blade or blender container; process until smooth. Return mixture to Dutch oven. Stir in tomatoes, corn, chiles and cilantro. Cook over medium heat for 5 to 7 minutes or until thoroughly heated, stirring occasionally.
To serve, ladle soup into 5 individual soup bowls. Top each with crisp tortilla strips.