This stock is excellent in meat soups and casseroles, and is ideal for hearty vegetarian recipes. It is easy to prepare and can be stored in the refrigerator for several days for use in a variety of dishes.
Preheat the oven to 180ºC. Put the wheat on a baking tray, spread out evenly and roast for 30 minutes or until the grains are dark brown.
Heat the oil in a large heavy saucepan over a low heat. Add the mushrooms and onions and stir to coat them in the oil. Cover the pan and sweat the vegetables for 5 minutes, shaking the pan occasionally.
Stir in the roasted wheat, carrots and celery. Pour in the water, increase the heat to high and bring the liquid to the boil, skimming off any scum that rises to the surface.
Reduce the heat to medium–low. Add the parsley, thyme, marjoram, bay leaves, peppercorns and salt. Cover the pan and simmer for 45 minutes.
Strain the stock through a fine sieve into a heatproof bowl. Use at once or leave to cool, then chill until required. The stock will keep in the refrigerator for several days.