Ok, so if you are looking at my pictures for this, you will see that I did not make this open-faced. I actually made a lot of changes to the original recipe, but after tasting it (and hearing from my cousin that the original was quite tasty), I want to try these again as written. The only change I would actually make next time is to spread some Russian dressing to the bread to make it more of a "sloppy joe" taste. I would also suggest grilling these as well.
My favorite part of this was the sauteed onions, I may use them as a topping on other burgers in the future. They added such a nice, sweet flavor to the burger! This is delicious paired with cole slaw, roasted zucchini or some oven-roasted chili fries.
Since I am recommending the original recipe I will just link you to it here: