French onion grilled cheese

This is based on a recipe from NYT cooking (I don't have a sub and I had to use the wayback machine to print it out). I cooked down 1 1/4 pound Vidalias, let it cool a bit, added it to 7 oz shredded gruyere "style" cheddar (the only option near me lol), and made four sandwiches with it. Served with homemade duck fat fries. Definitely recommend!