- Crush garlic clove, grate ginger root, chop coriander leaves and cut sweet potatoes in to medium sized chunks, set them aside. Preheat the oven at 356°F.
- Take a saucepan, boil water with sweet potatoes until tender. Meantime in a bowl mix harissa, lemon juice, garlic, butter and coriander. Mash potatoes when they are tender then add garlic and season it according to your taste.
- Take a roasting tin and place fillets of fish in it. Sprinkle salt as per your taste then drizzle butter mixture over it. Bake it for 8 minutes then serve it with mashed sweet potatoes.