Heat a heavy skillet over high heat, and when it's hot, add 2 tablespoons of vegetable oil. When the oil gets shimmery, add the four cups of corn. Season with Kosher salt and fresh cracked pepper.

Let this cook undisturbed for about 2-3 minutes, until the bottom layer begins to develop good browning. Stir and continue to cook undisturbed for another 2-3 minutes. Stir again and continue to cook until the corn is evenly browned with some charring. Maybe 2-3 more minutes.

Transfer charred corn to a large mixing bowl and add scallion greens, garlic, mayo, sour cream, and crema. Stir to combine and coat the corn in the sauce. Add cilantro and queso fresco, stirring between each addition.

Add chili powder to taste, stir, and serve warm or at room temperature.