In a small saucepan on medium heat, warm the 4 cups of turkey stock and white wine.
While the stock is warming, melt the butter In another heavy medium saucepan.
Add the onions to the melted butter and sauté on medium heat until translucent. About 5 minutes.
Add the garlic and thyme to the melted butter and continue to sauté for 1 more minute.
Turn the heat to low-medium and add the flour by sprinkling it on the onion mixture and cook while continually whisking for about 5 minutes.
Slowly add the warm stock and continue to whisk until completely combined.
Add one teaspoon of worcestershire sauce and the salt and pepper.
Continue to heat the gravy for 5 - 10 minutes until heated through.
Taste the gravy and only add the remaining teaspoon of worcestershire sauce and more salt and pepper if you want to. Or if you are preparing the gravy ahead of time, wait for this step and taste the gravy again before adding the seasonings.