Ridiculously Rad Roasted Eggplant Sandwiches

1. Preheat oven to 350 degrees F. Spray pan with cooking spray. You can brush a little bit of olive oil on the veggies at this point if you like. Place the eggplant slices on the pan and season to your liking with herbs and spices.
2. After you have seasoned the eggplant slices, place a slice of tomato on top of each eggplant slice. Put minced garlic on top of the tomato slices. Finally, place onion slices on top of the tomato slices and garlic. It should look like a weird pyramid. I think this is what makes the sandwich so delicious; the flavors and juices cascade down and get absorbed into the eggplant.
3. Roast in the oven for about 40 minutes. As I said earlier, I did not brush olive oil on the veggies. I don't think it will really affect much if you do add the olive oil as far as cooking goes, but it may slightly burn the veggies if you keep it in for the entire 40 minutes.
4. Remove from oven, place on hamburger buns, and enjoy! I topped mine with garlic hummus, but I believe that this is versatile enough to dress like a burger (mustard, ketchup, pickles, lettuce, vegan mayonnaise, etc.) or sauteed mushrooms.
Source of recipe: I was going to make an eggplant sandwich using the eggplant pomodoro recipe (http://vegweb.com/index.php?topic=11034.0). I didn't have any bread crumbs, so I made something else on the fly.