-shredded Salt & pepper to taste Drain and rinse clams, reserving juice; set aside. In a large kettle, saute onions in butter until tender. Add flour; stir to form a smooth paste. Gradually add the milk, stirring constantly until slightly thickened (do not boil). Add celery, parsley and potatoes and cook until tender, about 45 minutes. Add the clams and cheese; cook until cheese is melted and soup is heated through. Add reserved clam juice and salt and pepper.