As others have said, a cup of flour is way too much for gravy. But you might still be able to turn this into a yorkshire pudding.
That would depend on how much gravy you wish to make. The general rule of thumb is equal parts flour to fat. So for a cup of flour, you would need a cup of fat. You would also, of course, need a huge pot to make it in and a whole lot of liquid. I didn’t understand any of this the first time I made gravy (nobody told me not to use ALL of the turkey fat) and ended up with a huge amount of spackle. 
Not the way I make it: A cup of flour, a cup of milk, two eggs, and a little salt, with beef drippings for cooking it in.
I try to keep a few kinds of stock powder or concentrate around in case my sauce is lackluster or I don’t have enough drippings. Bovril is good, so is Better than Bouillon, but I really like Minor’s. Make a bouillon* of the stock powder in a small saucepan (or in the roasting pan you are deglazing)–50/50 water to wine is great. In the next pan, make a light to cafe au lait roux–I don’t really measure, but maybe 1/3 cup oil with a nice blob of butter, and a handful of flour. Combine slowly with a whisk. *A pinch of thyme or tarragon, or a bay leaf, or a stick of rosemary in the stock will perk it up. If you don’t add any wine, put a squeeze of lemon juice or wine vinegar in the stock.
That’s about it. I’m kind of resident saucier in my family…
Hot Pie for the win! I award you one internets.