I don't remember where I had a patty melt but I do remember the bread being toasted and pressed down. Much like some people make grilled cheese in a skillet.
But no onions. I do like the idea of caramelized onions included. It's something that can be cooked in a skillet and I'll use a brick to compress the sandwiches.
New Year's Day--Now is the accepted time to make your regular annual good resolutions. Next week you can begin paving hell with them as usual. - Mark Twain