First choose the ingredients to reflect the soup in which the broth is being used.
A general guideline for making vegetable broth is to use about 8 to 12 cups of vegetables cut into pieces no bigger than 1 inch.
Put these with 2 quarts of cold water in a large nonreactive pot with no more than six different herbs.
Bring to a boil over high heat, then lower the heat and simmer for 30 to 45 minutes. Strain and use as is or concentrate the flavor by simmering to the desired strength (by taste).
When using dried herbs, lessen quantities by one-half to two-thirds but always add *to taste*
Vegetable: carrots, celery, potatoes, winter squash, summer squash, chard, kale, tomatoes, mushrooms, eggplant, lettuce, green beans, capsicum, onion, zucchini, broccoli, babycorn etc. When available use fennel bulbs, asparagus, and peas
Herbs - basil, bay, borage, garlic, garlic chives, hyssop, lovage, marjoram, oregano, parsley, sage, savory, thyme spices (limit 2) coriander, cumin, cardamom, fennel seeds, whole cloves, cinnamon(limit to 6)
NOTES: Stock is very personal. It’s quickly prepared or make ahead and freeze in a size that’s convenient for you.
Cabbage family vegetables were left off the list of ingredients because they give a strong (dominant) flavor; the flavor grows stronger (ages in the freezer). If you like, use mild cabbages: Napa, pokchoy, a little savoy, young brussels. Or use chard and endive. When using cabbage, try to use the broth right away
Also, straining is important. Use a very fine sieve.