In a small bowl mix the butter together with half the grated nutmeg and 1 teaspoon of sugar and set aside until needed.
Prepare the yam by placing into boiling, salted water. Cook until tender. Drain well. In a medium pan add 4 tbsp of nutmeg butter, and spring onion and sauté for three minutes. Add the cooked yam and season well with salt and pepper. Keep in a warm place.
Heat half the olive oil along with 1 tablespoon of nutmeg butter in a pan, and sweat the onion, garlic and seasoning pepper until soft, with no colour. Add the chopped callaloo, and again cook until the vegetable is completely soft. Add the coconut milk, stock and the remaining sugar, and bring to a boil. Cook out gently for 10-15 minutes. Season with salt and pepper.
Heat a non stick frying pan with the remaining olive oil. Season the tuna well on each side and cook for 2 minutes on each side so that it still remains pink in the centre. Remove from the heat and add another 2 tablespoons of nutmeg butter to the pan, allow to melt and baste the tuna with this butter.
Now it’s time to serve, add a spoonful of warm yam to the plate, top with the tuna and serve another spoon of the callaloo sauce alongside.
Recipe courtesy of Dexter Burris