Wash mushrooms thoroughly being careful not to soak; remove stems. Over low heat, very gently sauté onions in 1/2 stick butter until translucent. In a small bowl, combine salt, pepper, lemon juice and soy sauce. Place mushrooms cap-side down on top of onions in large skillet. Fill each cavity with a pat of butter and sprinkle with lemon-soy mixture. Cover and cook on medium for about15 minutes. |