In a nonstick Dutch oven, heat the butter over medium heat and saute the leeks, celery, and thyme for about 1 minute. Sprinkle over the flour and stir until well coated. Add the potatoes, chicken broth, clams, clam juice, pepper and bay leaf. Simmer until the soup thickens, about 35 minutes.
While soup is simmering, heat a medium nonstick skillet over high heat and dry saute (with no oil or butter) the Canadian bacon until crisped.
Once soup has thickened, add the cream and remove bay leaf. Stir until well blended and remove from heat; be careful not to let boil. Garnish with green onions and crisped Canadian bacon. Serve immediately.