Really good sandwich. I used deli turkey and I had a nice wedge of gruyere that I used sliced instead of shredded and unfortunately I didn’t have any sourdough on hand. Even with those changes this was an amazingly good sandwich. The caramelized onions take it to a whole ‘nother level. Quick tip for fast caramelized onions, sprinkle a little baking soda (1/8 tsp) over the onions in the pan and they will brown quicker.