In a large pot or Dutch oven, cook bacon over medium heat until crispy. Remove bacon with a slotted spoon and set aside, reserving bacon fat in the pot.
Add butter to the pot and melt over medium heat. Add onion and cook until softened, about 5 minutes. Stir in flour and cook for 1 minute.
Gradually whisk in chicken broth until smooth. Add potatoes and bring to a simmer. Cook until potatoes are tender, about 10-15 minutes.
Add cod, scallops, and shrimp to the pot. Cook until seafood is cooked through, about 5-7 minutes.
Stir in heavy cream and cooked bacon. Heat through, but do not boil. Season with salt and pepper to taste.
Serve hot and enjoy!
Notes
For a thicker chowder, mash some of the potatoes before adding the seafood.