Preheat the oven to 220 C, 200 Fan, Gas 7. Rub a baking dish or roasting tray with a little olive oil. Season the cod on both sides and place in the dish.
Sprinkle the fillets with the basil, avocado and prawns, Drizzle over the cream and grate over the cheese.
Cook at the top of the preheated oven for 15-20 minutes until golden brown and bubbling.
Season to taste with sea salt and black pepper. Serve immediately.