Preheat your grill to medium-high heat
Husk the corn and remove the silk strands. Rinse the corn under cold water to clean off any remaining silk
In a small bowl, mix together the butter or olive oil, minced garlic, and a pinch of salt and pepper
Brush the corn with the butter or olive oil mixture, making sure to coat all sides
Place the corn on the preheated grill and cook for about 10-12 minutes, turning occasionally, until the corn kernels are lightly charred and tender. Remove from the grill and set aside to cool slightly
Once the corn has cooled down, cut the kernels off the cob. Hold the corn vertically on a cutting board and use a sharp knife to slice downward, separating the kernels from the cob. Transfer the kernels to a large bowl
Add the lime juice, crumbled cotija cheese, finely chopped serrano peppers, red onion, and chopped cilantro to the bowl with the corn
Toss all the ingredients together until well combined. Make sure the cheese, peppers, and cilantro are evenly distributed throughout the salad
Season with salt and pepper to taste. Start with a small amount and adjust according to your preference
Let the grilled street corn salad sit for about 10-15 minutes to allow the flavors to meld together
Serve the salad at room temperature or chilled