Add olive oil and butter to a large skillet over medium heat. Add the corn and cook until the corn starts to char, stirring often, about 8 minutes. Remove from heat.
In a large bowl, combine corn, cooked quinoa, red onion, roasted peppers, cheese, jalapeno and cilantro. Fold in the dressing. Squeeze lime juice over top and toss again. Add to serving bowl. Sprinkle with extra Cotija cheese. Serve.
In a small bowl, combine all dressing ingredients and whisk until well blended. Serve.