In a large saucepan over medium heat, cook the chopped bacon until wonderfully crisp. Use a slotted spoon to transfer the cooked bacon to a paper-towel-lined plate to drain, keeping the drippings in the pan.
Add the finely chopped onion and turnip cubes to the bacon drippings in the saucepan. Cook for about 5 minutes, stirring occasionally, until the onion becomes tender.
Pour in the chicken broth. Bring to a gentle simmer and let it cook for 10-15 minutes, or until the turnip cubes are fork-tender. Stir in the dried thyme, salt, and pepper. Taste and adjust seasoning as needed.
Gently add the fish pieces (or drained clams) to the simmering chowder. Continue to simmer for about 3-5 minutes, just until the fish is opaque and cooked through, being careful not to overcook.
Stir in the heavy cream and butter until fully incorporated and melted, making the chowder deliciously creamy and rich.
If a thicker chowder is preferred, remove about 1/2 cup of the hot broth into a glass measuring cup. Vigorously whisk in the glucomannan or xanthan gum until smooth. Stir this mixture back into the pot and let sit for a few minutes to thicken.
Ladle the warm chowder into bowls. Sprinkle each serving generously with the crispy bacon bits set aside earlier. Enjoy this comforting and healthy meal!