For the corn: Prepare a grill for medium-high heat.
Brush the corn with olive oil and sprinkle with salt and pepper. Grill until cooked and browned, about 10 minutes. Set aside to cool.
For the salad: Add the tomatoes, onions, pepper and jalapeno to a bowl. Pour over the olive oil and lime juice, sprinkle with a pinch salt and pepper and toss.
Cut the corn off the cobs, leaving some in shards, then toss gently with the salad, keeping the shards intact. Sprinkle over the cilantro leaves and gently mix in.