Peel and finely chop the onion and garlic. Wash and chop mushrooms. Peel yellow beet and cut into small cubes. Wash and strain the rolled barley.
Now put all ingredients in an unperforated container and steam at 100 °C for about 40 minutes.
Season with salt, pepper and olive oil and serve the finished rolled barley stew hot, decorated with fresh marjoram.