In a large, heavy pot, heat the olive oil on medium high and add cubed bacon. Sweat the bacon for 5 minutes, stirring constantly. Add chopped onion, minced garlic, peeled and cut carrots, cut celery and cubed potatoes.
Sweat all the vegetables for 10 minutes on medium heat, until lightly brown, stirring frequently. Add ground thyme, ground mustard, bay leaves and all-spice balls. Stir and cover with the lid for 5 minutes.
Add vegetable or chicken stock and cover the Dutch oven with a lid. Let simmer the vegetables for 15 minutes, or until the potatoes and other vegetables are soft.
Optional: In the meanwhile, you can season with salt the fish and dust it with flour, then fry the fish on a pan. Approximately 3 minutes from each side.
Place the fish in the vegetable stock and cook for another 5 minutes. Add either regular milk or coconut milk to the soup to add texture and stir. Season with salt and pepper, if needed.
Remove the Dutch oven from the heat and let it stand on the stove for another 15 minutes covered with the lid. Serve with piece of fresh bread.