Blanch the bones in sparkling water. Then drain, rinse with cold water and boil up with 1.5 l of cold water. Add the meat, bay leaf, peppercorns and just a little salt. Do not let the broth boil fizzy, but simmer open only slowly for about 2 hours, otherwise it will become cloudy. Remove the resulting foam again and again with a skimmer.
Clean, wash and chop the vegetables and simmer for the last hour. Pour everything through a fine sieve. Season to taste with salt and pepper. Let it cool down. Freeze in portions if necessary.