In 12-inch nonstick skillet, melt butter over medium-high heat. Stir in onion, bell pepper and serrano chile; cook about 3 minutes or until vegetables are just softened. Add chicken; cook 4 to 5 minutes, stirring frequently, until chicken is cooked through. Reduce heat to medium. Stir in flour and taco seasoning mix; cook 1 minute, stirring constantly. Gradually beat in broth and whipping cream with whisk. Heat to boiling, stirring constantly; boil and stir 1 minute. Remove from heat; stir in cheeses until melted. Stir in frozen corn.