Sorrel is one of my favorite wild greens. It has such a refreshing, lemony tartness that will go very well with the sweet corn and fresh cheese.
Combine corn, onions, and sorrel in large bowl, and set aside.
In a separate bowl, whisk together vinegar, mustard, and seasonings until smooth. Slowly pour oil into vinegar mixture while continuously whisking. Continue to whisk until emulsion is set.
Add dressing to corn mixture slowly until desired consistency is reached. Divide into plates or bowls before grilling cheese.
Lightly oil and season Queso De Verano, and grill on a hot, clean grill. 3-5 seconds each side, or until dark grill marks appear. It is very important not to let the cheese melt.
Top salad with grilled cheese.