From: The Naked Chef Takes Off by Jamie Oliver, 2000, ISBN# 1-4013-0824-4
Half-fill your largest pot with roughly chopped fragrant vegetables such as celery, fennel, carrots, onions and leeks and plum tomatoes. Add garlic, herbs and spices such as thyme, rosemary, bay, parsley and chili. If you have any dried mushrooms add them too, as they give an amazing flavour. Cover with cold water, bring to the boil, and then simmer for 1 – 3 hours with a lid on the pan. Vegetable stock will keep in the fridge for a week and in the freezer for 2 – 3 months.