Cook fresh fish 10 min., drain, save water. SEt fish to cool as this is added last, just before serving to eliminate breaking up.
Fry out salt pork, cut into small cubes; remove cubes after the become brown and set aside to be served separately.
Slice onions and fry lightly in pork fat;add cubed potatoes to onion mixture and the remaining fish water, cooking until potatoes are tender
Add regular milk, evaporated milk and butter and let stand several hours, if possible, for flavor
This mixture can be divided in half at this point to two large double boilers so your chowder may be reheated without scorching.
At this time mix the flour and water to thicken slightly the chowder so that it is not a sloppy mixture; and the very last thing add the 15 pounds of fish.Stir as little as possible so that fish is not broken up. Four pounds of crackers or pilot bread will be needed to serve with this and of course nice dill or sour pickles.