Boil Potatoes in water for 10 minutes. Drain and set aside. In a large, heavy pot, saute bacon, onions, and celery over medium-high heat until celery is tender.
Drain bacon grease and return bacon, onions, and celery to pot. Add milk, water, chicken base, salt and pepper.
Heat over medium-high heat until very hot. Do Not Boil. In a heavy, large saucepan, melt margarine and add flour (called a roux). Mix well. and allow to bubble, stirring for 1 minute.
While constantly stirring soup, add the flour & margarine mixture (roux) slowly. Continue stirring soup until thick and creamy. Add in the heavy cream. Stir in potatoes and parsley.
Serve while hot. Garnish with shredded Colby cheese, fried bacon bits, and chopped green onions or all three. My personal suggestion: all three is the best.