In 12-inch nonstick skillet, heat oil over medium-high heat. Add chicken wings and onions; sprinkle with pepper flakes. Cook uncovered 5 to 8 minutes, stirring occasionally, until browned; drain.
Stir in carbonated beverage, green chiles and taco seasoning mix. Increase heat to high; cook uncovered 15 minutes, stirring occasionally. Reduce heat to medium-high; cook 5 to 10 minutes, stirring frequently, until chicken wings are completely glazed, small amount of glaze remains in skillet and juice of chicken is clear when thickest part is cut to bone (180°F).
To serve, line serving plate with lettuce; arrange chicken wings over lettuce. Serve immediately.