8 oz. mushrooms, sliced in 1/2 inch slices (I used brown crimini mushrooms, but any mushrooms will work)
1 lb. fresh green beans, preferably thin French style beans
1 1/2 T olive oil
1 T balsamic vinegar
salt and fresh ground black pepper to taste
2 T finely grated parmesan cheese
Put cut beans and mushrooms into a Ziploc bag or plastic bowl. Whisk together olive oil and balsamic vinegar and pour over, then squeeze bag or stir so all the beans and mushrooms are lightly coated with the mixture. Arrange on large cookie sheet, spreading them out well so beans and mushrooms are not crowded. Roast 20-30 minutes, starting to check for doneness after 20 minutes. Cook until beans are tender-crisp, mushrooms are cooked, and all liquid on the pan from mushrooms has evaporated. Season beans to taste with salt and fresh ground pepper, then sprinkle with finely grated Parmesan. Serve hot.