Rinse the fish and cut into bite-sized chunks. Remove the corn from the freezer to take some of the chill off while preparing the basic chowder. Set both aside.
Melt 1 T butter in a large stock pot. Saute the onion, celery and garlic until almost translucent. Add the bell peppers and continue to saute until all are soft.
Add the broth, water, potatoes, and seasonings. Bring to a boil.
Reduce heat, cover and simmer until the potatoes are tender, about 25 minutes. (If desired, mash some of the potato to additionally thicken the chowder).
In a bowl or jar, mix the flour and milk until smooth. Pour this and the evaporated milk into the chowder.
Add the fish, corn, and remaining 2 T butter. Bring to a boil, reduce heat and cook, stirring gently, another 5 to 10 minutes until fish is cooked through and chowder is thickened slightly. Remove bay leaf before serving.
Garnish with fresh parsley or dill. Pass Tabasco at the table.