Wash and drain peas. Cover with cold water and soak overnight or according to package directions. Drain and place in large kettle with 3 quarts water. Slowly bring to a boil. Cooked covered over medium heat for 1 hour. Skim off pea skins as they float to the top. Add bacon or salt pork. ( If pork is very salty, soak in cold water for 30 minutes, drain and pat dry.) Cover soup and simmer over lowest possible heat for about 2 hours, stirring occasionally. the peas should be of puréed consistency. Add celeriac or celery, leeks, carrots, potatoes, onions, thyme and Canadian bacon to soup during last 45 minutes of cooking time. Stir soup occasionally and check for desired consistency; if necessary, add a little hot water. When ready to serve, remove bacon or salt pork and Canadian bacon to heated platter and slice. Serve soup and sliced meats separately. The meats may also be served cold, if desired.

Note: In Denmark it is usual to start with a plate of soup alone. Then, a second plateful of soup is eaten alternately with the meats ( you sip a little soup, eat a little meat and so on). Serve with a good sharp mustard, pickled beetroot, rye bread and sweet butter.
Serves 6 to 8.