French onion grilled cheese

We made french onion grilled cheese sandwiches from Rachael Ray last week. They are simple to make, as long as you're patient enough to let your onions caramelize (20 minutes or so). I made a few substitutions based on what we had on hand: brie cheese instead of camembert, sourdough bread instead of regular white, and fontina cheese instead of gruyere. Yum!