Balsamic Vinegar & Mushroom Steak Sauce
Chopped for garnish
Melt butter in a saucepan over medium heat.
Saute onions until they start to turn translucent.
Add garlic, saute until they start to brown.
Add sliced mushrooms; cook until the edges start to turn brown and mushrooms soften.
Add balsamic vinegar and 3/4 of the can of beef broth; reserve the rest for later.
Lower heat and simmer mushrooms until the liquid is reduced by a quarter or more. About 15 minutes. Stir constantly scrapping the bottom of the pan so keep sauce from burning.
Dissolve corn starch in the remaining beef broth and slowly stir in to the mushroom mixture. It should thicken slightly.
Remove from heat, pour into bowl or gravy boat. Garnish with parsley and serve.