In a soup pot, melt butter over medium heat. Add onion, celery, leeks and garlic. Sauté for 3 minutes, mixing often.
Remove from heat and add flour, mixing well.
Add milk and whisk vigorously.
Drain clams and add juice to soup.
Slowly bring to a boil, mixing often. Reduce heat to a simmer.
Add potatoes and seasonings; simmer 10 minutes.
Add clams and simmer 5-8 minutes.
Finish with heavy cream. Serve.
Makes: 4