Line a large frying pan with a thin layer of water or broth. Add onion and garlic and sauté over high heat for 2 minutes.

Add 1 cup water or broth, vinegar, mirin (or sherry) and herbs and reduce heat to medium. Add mushrooms, cover and cook for 5 minutes.

Gently flip over and cook for 5 minutes more, adding additional water or broth as necessary to prevent sticking or burning.

Flip mushrooms a third time if desired (cook until mushrooms are fork tender and juicy). Plate, spooning pan juices over top.