Gather all ingredients before starting recipe.
Combine red wine, vinegar, soy sauce, sugar, Asian chili sauce in a medium sauce pan.
Bring to a boil and then reduce to a simmer and cook until reduced by half, about 30 minutes.
Add reserved mushroom juice (if serving with wild mushrooms) and chicken stock and reduce to 3/4 of a cup, another 30 minutes. Check for seasoning.
Combine 1 -2 tablespoons of corn starch with 3-4 tablespoons of water and stir to combine into a slurry. Bring the sauce to a fast simmer and add some of the slurry a little at a time, stirring constantly, until the sauce coats the back of a spoon.