I’m extremely frugal, so in my eyes, wasting food is criminal. I always try to cook with ingredients already on hand, and this grilled cheese is a result of that. Using leftovers and items I needed to get rid of, I whipped up this cheesy and delectable grilled cheese. The caramelized onions stole the show, but the truffled fried potatoes came in a strong second. Of course, the gooey Gruyere cheese played its part, too!