Spray a medium-sized stockpot with the cooking spray. Over medium heat, add the Canadian bacon and cook until lightly browned and slightly crisp, stirring constantly. Add the butter, onions, celery and thyme. Cook 5 minutes, or until the onions are soft and translucent.

Using a wire whisk, whisk in the flour and continue to cook and stir a minute or two until the flour is incorporated and all the vegetables are coated (the mixture will be quite paste-like at this point).

Pour in the clam juice, one bottle at a time, whisking the liquid into the vegetable mixture until it’s well combined before adding the next bottle of clam juice. (It will be very thick at first; don’t worry, it thins out just fine). Continue until all clam juice has been incorporated, then reduce the heat to medium-low.

Add the monosodium glutamate and the diced potatoes. Simmer mixture 10 to 15 minutes, or until potatoes are tender, stirring and scraping the bottom of the pot occasionally.

Cut the fish into bite-sized chunks. Add the fish pieces to the pot and cook another 5 to 10 minutes or until all fish pieces are cooked through. Stir in the fat-free half-and-half, adding more if you prefer a thinner consistency. Add pepper; taste and adjust the seasonings. Ladle chowder into bowls and garnish with chopped chives or green onions, if desired.