Microwave the corn with the husk on for 10 minutes;
Boil the corn for about 3 -4 minutes with a little salt added to the water or grill lightly for a roasted flavor.
Let the corn cool until you can handle them and cut the kernels off the cob into a large bowl.
In a small bowl make the vinaigrette by whisking together butter, lime juice, chili powder, and chopped cilantro. Add the vinegar and whisk in the olive oil until emulsified to taste.
Pour the vinaigrette over the corn and mix to coat.
Add the tomatoes and crumbled queso fresco or grated Jack cheese and stir. Season with salt to taste.
Serve at room temperature. Refrigerate leftovers.