Heat oven to 450°. Place turkey trimmings, carrot, celery, onions, and garlic in large oven-safe dutch oven. Drizzle on olive oil and toss to combine. Roast, stirring every ten minutes, until well-browned, 40 to 50 minutes.

Remove pan from oven, and place over burner set at high heat; add stock and bring to boil, scraping up browned bits on bottom of pan with wooden spoon. Add wine, three cups water, and thyme; bring to boil over high heat. Reduce heat to low and simmer for an hour and a half. Strain stock into large container. Cool to room temperature; cover with plastic wrap and refrigerate until fat congeals, at least an hour.

To finish gravy, skim fat from stock using soup spoon; reserve a half cup of fat. Bring stock to simmer in saucepan over medium-high heat. In second saucepan, heat reserved turkey fat over medium-high heat until bubbling; whisk in flour and cook, whisking constantly, until combined and honey-colored, about two minutes. Continuing to whisk constantly, gradually adding hot stock; bring to boil, then reduce heat to medium-low and simmer, stirring occasionally, until slightly thickened, about five minutes. Season to taste with salt and pepper.

Advance prep: One of the lovely things about this gravy is that it can be made in advance and refrigerated up to three days. Reheat in medium saucepan over medium heat until hot, about eight minutes.