Heat the coconut oil in a deep fry pan.
Add the onion, ginger, garlic, cumin, ground coriander, mustard seeds, bay leaf, turmeric and chilli.
Sauté for a few minutes until it becomes fragrant.
Add the diced potato and zucchini and cook for around 5 minutes.
Add the coconut milk and stir well to disperse the spices through the milk.
Bring to a simmer and add the diced fish.
Continue to simmer the curry for around 10 minutes, or until the fish is cooked through.
Remove the bay leaf.
Sprinkle the tapicoa flour through the sauce and stir well until starts to thicken.
Taste the curry and season with a little sea salt and pepper to taste.
To serve sprinkle with fresh coriander leaves.