Par boil sweet potato, allow to steam dry then cut into even slices. Pat fish dry and season with salt and pepper. Dissolve icing sugar in white wine vinegar, skin and dice plum tomato, finely dice spring onion, combine with vinegar mix, add olive oil and allow to macerate for a short while. Heat oil in a pan and begin frying sweet potatoes for 3-4mins each side or until slightly coloured. In a separate hot pan, sear the seabass fillets skin side down until it begins to crisp, turn the fish, lower heat and allow to finish cooking. Meanwhile drain sweet potatoes on kitchen towel and arrange on a warm plate. Place seabass fillets on top, drizzle with macerated tomato & spring onion and garnish with fresh basil leaves and lemon wedges.