Preheat your oven to 400°F or prepare a grill for medium-high heat. Husk the corn and brush it lightly with olive oil. Roast the corn for about 20 minutes or grill for 10–12 minutes until slightly charred. Let cool and shuck the kernels into a mixing bowl.

In a medium bowl, whisk together ¼ cup of olive oil, ¼ cup of mayonnaise, 1 tablespoon of Tajin seasoning, and juice from one lime until smooth and creamy. Adjust the salt to taste.

With the warm corn kernels, add ½ cup of chopped cilantro and ½ cup of finely diced red onion to the mixing bowl. Pour the creamy lime dressing over the mixture and fold gently to combine.

Taste and adjust seasoning if needed. Serve immediately at room temperature or chill in the refrigerator for 30 minutes for enhanced flavors.