I've cobbled this recipe together with ingredient inspirations from other turkey roast recipes posted on this site. I was amazed at how tasty and moist this was, so thought I'd share my variation. The mushroom and garlic portion of the recipe is optional; you may want to throw in other veggies instead of, or in addition to, those i've used (e.g., a couple of carrots, broccoli stalks, red peppers, potatoes, etc...).
Warning: This is not going to generate much towards a gravy, so don't get your hopes up! Also, butter may not be as healthy as olive oil--but it sure adds flavor.