Gather the ingredients.
Cut the thawed fish fillets into bite-sized pieces.
Place in the slow cooker.
Dice the bacon or salt pork into small pieces.
In a large skillet over medium heat, fry the bacon or salt pork with the chopped onion until the meat is cooked and onion is golden.
Drain and discard excess fat.
Transfer the bacon and onion mixture to the slow cooker with the fish pieces.
Add the cubed potatoes, water, salt, and pepper.
Cover and cook on low for 5 to 6 hours, or until the potatoes are tender.
Add the can of evaporated milk and cook for another 30 minutes to 1 hour, or until hot.
Serve and enjoy!