Halve the onion. Brown the cut surfaces in a large pot. Clean or peel, wash and cut the soup vegetables into pieces. Wash and halve the tomatoes. Wash oregano and rosemary. Add soup vegetables and tomatoes to the onion.
Add wine and approx. 1 1⁄2 l of cold water. Season with 1 tsp. salt, rosemary, oregano, bay leaf, juniper, cloves and peppercorns. Bring the stock slowly to the boil. Simmer gently for about 30 minutes. Pour through a fine sieve into a fondue pot.