Heat your oven to 400F. Line a baking tray with foil. Toss the sweet potato in a little oil and seasonings of your choice. Lay out in a single layer and roast for 15 – 20 minutes.
For the fish and sauce
Add the leeks and a little oil to a medium heat skillet. Make sure that it’s deep enough to fit all the ingredients except the sweet potato!
Add the garlic and lemon pepper to the pan and saute for 10 minutes until softened.
Nestle the cod fillets into the leek mixture, reduce the heat a little so that the coconut milk will continue to simmer with a lid over the pan but not burn.
Add the cilantro and cover the pan with a lid, leaving a little gap for steam to escape if needed.
Cook for five minutes. Flip the fish over and cook for another minute or two until the fish is opaque and will flake with a fork.
Optional step: Add the arrowroot starch mixture and simmer for an additional few minutes to thicken. Remove the fish before you do this or it will be overcooked!