Melt butter in a large Dutch oven over medium-high heat. Add onions, bell pepper and serrano chile to pan; saute' 2 minutes or until tender, stirring frequently. Add canned chiles to pan; cook 1 minute. Add flour to pan; cook 1 minute, stirring constantly. Stir in milk and next 5 ingredients (through corn); bring to a boil. Cook 5 minutes or until slightly thick. Stir in shrimp; cook 1 minute or until shrimp are done. Remove from heat; stir in cilantro.