How to Make It
Preheat the oven to 350°. Generously butter a shallow baking dish large enough to hold the fish fillets in one layer. Arrange the fish fillets in the dish, top with the butter slices and drizzle with the olive oil. Season the fish with pepper and scatter the parsley and thyme on top. Bake for about 10 minutes, or until the fish is just cooked through.
Preheat the broiler. Sprinkle the fish fillets with the grated pecorino. Broil for about 2 minutes, or until the cheese is golden brown. Let the fish fillets stand for 5 minutes, transfer to plates, grate the bottarga on top and serve.