To grill the corn, heat the grill over high heat. Place the ears directly on the grill and cook until they are just charred, turning often. This will take about 8 to 10 minutes. You can use leftover corn or fresh corn too! Once the ears are cool, slice the corn off the cob.
Stir together the softened butter, cilantro, lime zest and a big pinch of salt. Mix until combined.
Spread the outsides of the bread with the cilantro lime butter. Heat a large skillet or griddle over medium-low heat. Place 2 slices of the bread butter-side down in the skillet, top with the cheese, the corn and the green onions. Top with the remaining slices of bread, butter-side up.
Cook over low to medium-low heat, doing so slowly until the cheese melts. Once the bottom is golden and toasty, flip and cook until the other side is golden too.
Remove immediately and top with cotija cheese, a sprinkle of chili lime seasoning and fresh cilantro. Serve and enjoy!