Leek and Potato Soup

3ozs Butter
1 lb Leeks washed trimmed & peeled
2 sticks celery chopped
1 lb Potatoes peeled & chopped
2 pints Chicken stock
¼ tsp Curry powder (mild or medium)
¼ tsp Nutmeg
½ tsp sugar
½ tsp Black Pepper
Salt
Melt butter and sauté leeks, celery and potato for 8-10 minutes (do not brown).  Pour in stock and bring to the boil.  Add curry powder, nutmeg, sugar and seasoning.  Reduce heat and simmer for 30 minutes.  Puree or liquidise