Husk the corn and grill, turning often until lightly charred

Cut kernels off corn and transfer to a medium bowl

Cut the onion and red bell pepper into medium dice and add to the corn

Cut stems off serrano chili and slice across into thin slices and add to mixture

Remove leaves from cilantro stems and mince

Mince the chipotle chilies and add to corn along with cilantro, lime juice, corn oil and salt and pepper to taste. Let stand at room temperature at least 30 minutes or refrigerate at least 1 hour and up to 2 days

Serve at room temperature.