Line a medium glass bowl with 1 tortilla. Prick bottom of tortilla with a fork. Microwave at HIGH 1 1/2 minutes or until crisp. Repeat with remaining tortillas.
Bring water to a boil in a saucepan. Add chiles; cover, remove from heat, and let stand 30 minutes. Place chile mixture in container of an electric blender; cover and process until smooth. Set aside.
Sprinkle meat with salt and pepper. Place flour in a zip-top plastic bag; add meat. Seal bag; shake to coat.
Coat a Dutch oven with cooking spray; add oil. Place over medium-high heat until hot. Add meat; cook until browned. Remove meat from Dutch oven; set aside. Add 1/2 cup broth to Dutch oven; cook over high heat, deglazing Dutch oven by scraping particles that cling to bottom. Add chile mixture, meat, remaining broth, onion, and next 3 ingredients. Bring to a boil; cover, reduce heat, and simmer 1 hour or until meat is tender. Add corn; simmer 3 minutes. To serve, spoon chili into tortilla bowls. Garnish with fresh oregano, if desired. Yield 5 (1 1/4-cup) servings.