Heat a large skillet over high heat and add the corn kernels, cooking for 4-5 minutes without stirring until charred spots appear, then set aside to cool.
Soak the diced red onion in a bowl of cold water for 5 minutes, then drain well to remove the harsh bite.
In a large bowl, combine the charred corn, drained red onion, bell pepper, jalapeño, and cilantro.
In a small bowl, whisk together the lime juice, olive oil, cumin, salt, and pepper until combined.
Pour the dressing over the corn mixture and toss well to coat all ingredients evenly.
Refrigerate for at least 30 minutes before serving to allow flavors to develop, then serve with tortilla chips.