I didn't grow up in a gravy family except for milk gravy for fried chicken and pork chops. So the Thanksgiving demand for gravy when I became the sub-matriarch and chief cook in the Pollack family in 1994 left me surprised and coming up a little short, at least in my own assessment. (The family gravy maker, the middle daughter, had her own family - far away - by then.)
Over the years I've tried various things using the pan juices, some of which worked out reasonably well but all of which were too salty for many of the diners. My matriarchal line was notorious for having a horror of too-dry dressing for the bird, and I can just hear my grandmother sniffing, "No wonder they have to have gravy. That dressing was so dry they'd choke on it." Consequently my dressing is, more or less, a moist, savory bread pudding. (Neither family did mashed potatoes for the meal Both Joe's parents and mine were public school teachers; perhaps too many cafeteria meals had killed their appetite for them, even though that was long before the instant kind.)
After a couple of years of not having Thanksgiving here, I'm back in the saddle again, at least in a somewhat abbreviated form. And I think I may have the answer to the problem. This comes from Food & Wine magazine some years ago, and produces a rich, flavorful broth that's amazingly good even freshly cooked and unseasoned beyond what went into the stock pot. I didn't follow the recipe to the letter, both by choice and accident, but the results are worth the effort, which frankly isn't much, especially if you're doing this a couple of weeks beforehand.
a couple of turkey drumsticks and some necks and/or wings to total 4-6 lbs.
2 garlic cloves
a stick of celery
(they added a carrot at this point; I forgot)
several stalks of parsley
a bay leaf
Preheat your oven to 400 degrees. In a pan you can put over a burner later, roast the turkey parts for about an hour, until they're browned. Transfer the turkey to a stock pot. Slice the onion and garlic, chunk up the celery, and toss in the parsley and bay leaf. Take a cup or so of water, add it to the roasting pan, and warm the pan and stir so that the wrming liquid helps loosen the browned bits. When the bits are loose and the liquid is bubbling, add it to the stockpot. Add more liquid to the stockpot to cover the solid ingredients - this will probably be about 10 cups. Please note there's no salt added. Season the gravy when you're close to serving it.
Bring to a boil, drop the heat to let the contents of the pan simmer gently and partially cover the pan. Let it cook for about 2 1/2 hours. Strain the stock, discard the solids (or save the turkey for the cat) and chill the stock. Remove the solidified fat and freeze the liquid.
This should yield about 2 quarts, and, of course, can be supplemented with the juices from the roasted turkey.