Preheat oven to 375°F (190°C).
Fry the garlic in the coconut oil in a saucepan. Whisk in the flour, followed by the coconut milk. Cook, while stirring, until the sauce thickens to your liking. Season with salt and pepper.
Combine the salmon with the carrot, celery, onion and chives. Season.
In a casserole dish start with a layer of potato slices. Top with some of the coconut sauce.
Add half the salmon mixture, then another layer of potatoes, then sauce, then salmon, then potatoes and then the rest of the sauce on top.
Bake for 45-60 minutes.