Heat the oil in a large cast-iron skillet over medium-high heat until shimmering. Add the corn and cook, stirring occasionally, until toasted and golden brown, about 15 minutes. Add the garlic and cook for 1 minute more. Remove the skillet from the heat and allow the corn to cool for a few minutes.Transfer the corn to a large bowl. Add the cilantro, jalapeño, cheese, French sauce, and chili powder and stir to combine.