Mince well rinsed leeks, primarily the white part. Saute in parve butter for 2 minutes or less. Peel and finely slice or dice potatoes. Add to leeks. Add chicken stock. Boil covered, low temperature 15 minutes or until tender. Let cool. Put parsley (preferably flat) in food processor and process. Add stock, vegetables, non-dairy creamer, pepper and salt. Process until smooth. Serve either hot or cold.