Pour off all but 4 tablespoons fat from pan drippings. (If you don't have 4 tablespoons fat in the pan drippings, add butter to compensate.) Place the roasting pan over medium heat and sauté onion and garlic until tender, 5-6 minutes. Sprinkle with a bit of salt and pepper.
Add flour and completely mix all ingredients. Cook the flour with the vegetables for about 1 minute. Add wine and scrape up all the bits stuck to the bottom of the roasting pan with a wooden spoon. Whisk in the broth and simmer until thickened, 2-3 minutes. Season with additional salt and pepper, as needed. Serve warm.