When the turkey is finished roasting, I take the pan drippings and roasted veggies for the gravy. First, I drain the vegetables but make sure to keep the liquid. The liquid goes into a bowl where the fat can be separated. The fat/oil floats to the top and can be skimmed.
The vegetables goes into a blender and processed finely. A food mill would work really well here too. I would prefer one too but I don't own one...yet. Then I bring, the turkey juices, some stock, and half of the pureed vegetables to a boil. If the gravy doesn't look thick enough, I'll add some flour to the rest of the vegetables. Then I'll add that mixture to the boiling gravy. Make sure this boils too to ensure that the flour will thicken the sauce. The gravy is thick and super flavorful. My only gripe is that it's orange from the carrots.