Heat 1 tablespoon olive oil in a medium saucepan over medium heat. Add garlic and onions, cooking until softened and stirring frequently. Remove the onions and garlic from the pan and set aside.

Turn up the heat to medium high, add 1 tablespoon olive oil. Then add the mushrooms and cook until lightly browned and softened. At this point, most of the water from the mushrooms should have cooked off.

Add the onions and garlic back to the pan with the white wine, cooking over medium high heat until the liquid is reduced by half.

Reduce the heat to medium. Add the broth, milk and miso to pan and cook until bubbly. Remove a quarter cup of liquid and mix in the cornstarch, whisking until smooth.

Add to pan, stirring to combine. Bring to a low boil and cook for two minutes. Sauce will thicken as it cooks. Add one tablespoon fresh thyme and black pepper as desired. Taste and add salt as to taste.