Step 1

In a large skillet over medium high heat, heat the olive oil. Add the onions and saute for 3 minutes.

Step 2

Add the mushrooms and continue to cook on high for 5 minutes, more stirring occasionally. Onions should become clear and the mushrooms should give up their liquid and start to brown lightly. Season to taste with salt and pepper.

Step 3

Add the balsamic vinegar and and herbs and stir, scraping up any browned bits. Cook 5 minutes more on medium heat until the liquid has evaporated.