Add garlic and saute until onion is translucent about another minute or two.
Add red wine and cook one minute, stirring constantly. Stir in remaining 3 cups of broth and bring to a boil, reduce heat and simmer.
Paste
Meanwhile, in a small bowl, whisk together tamari, yeast and flour to form a thick paste.
Add mixture to pan, whisking constantly to make sure the paste dissolves. Bring to a boil and boil another minute, stirring constantly. Add salt and pepper.
Adjust seasonings.
If you prefer it thicker, thicken with flour or cornstarch. 1 tablespoon flour (or cornstarch) to 1 tablespoon of water to make a paste and add. Keep adding and whisking to desired thickness.
Recipe by Ordinary Vegan at https://ordinaryvegan.net/veganbreadstuffing/