In a medium-sized bowl, combine Greek yogurt, mayonnaise, lime juice, minced garlic, chili powder, salt, and black pepper. Whisk together to create the sauce and set aside.
Heat olive oil in a large pan over medium-high heat. Once the oil is hot, add corn kernels, ensuring they spread out in an even layer. Cover the pan with a lid and cook for 3 minutes.
Remove the lid, stir the corn, cover again, and cook for an additional 3 minutes. Be careful when removing the lid, as the corn kernels may pop.
Remove the pan from the heat and let it cool for about 5 minutes. After cooling, add the corn to the prepared sauce and stir until well mixed.
Incorporate the serrano or jalapeno pepper, sliced green onions, chopped cilantro, and crumbled feta or cotija cheese into the mixture. Stir until all ingredients are evenly distributed.
Serve the salad on a serving plate, garnished with extra cheese and fresh cilantro.