Preheat a grill to medium or preheat the broiler. Grill (or broil on a foil-lined rimmed baking sheet) the corn, chile, pineapple and onion, turning occasionally, until the corn, pineapple and onion are lightly charred and the chile is well charred and its skin is beginning to split, about 10 minutes. Transfer the corn, pineapple and onion to a plate and the chile to a small bowl; cover with plastic wrap and let cool.
Cut the corn kernels from the cobs. Chop the pineapple and onion. Place in a bowl. Peel, seed and finely chop the chile; add to the corn mixture with the EVOO; season with salt and pepper.