How to Make It
In a medium saucepan, simmer the corn cobs in 1 cup of water until the broth has reduced to 1/4 cup, about 10 minutes. Strain the broth; discard the cobs.
Meanwhile, in a blender, combine the mayonnaise with the cilantro, lime zest and lime juice and puree until smooth. Season with salt.
In a cast-iron skillet, heat the oil until smoking. Add the corn kernels and peppers and season with salt. Cover and cook over moderately high heat until the corn starts to pop, 2 to 3 minutes. Stir the corn, cover and cook until the corn is lightly charred, about 2 minutes longer. Add the corn broth and simmer until nearly evaporated, then stir in the butter. Season the corn and peppers with salt and pepper.
Transfer the corn and peppers to a bowl, drizzle with some of the cilantro- lime mayonnaise and serve.