1Cook the pasta according to package instructions until al dente. Drain and toss with a little olive oil and a pinch of salt. Set aside to cool in the refrigerator.
2In a bowl, mix together mayonnaise, sour cream, lime juice, grated garlic, chopped green onion, tajin, cumin, salt, and pepper to make the dressing. Set aside.
3Heat a skillet over medium heat and add olive oil. Add frozen corn, season with salt and pepper, and cook, stirring occasionally, until the corn is heated through and slightly charred.
4In a large bowl, combine the cooled pasta with enough dressing to coat. Add the charred corn, chopped cilantro, and cotija cheese. Toss well to combine.
5Serve chilled. If making ahead, add extra dressing before serving to freshen it up.