Season the fillets on both sides with salt and pepper. Spread the tops with black bean paste. Place fish into heatproof dish, add sake and steam for 10 minutes over high heat in a steamer.
While fish is steaming, use a vegetable peeler to slice the ginger into very thin slices, then use knife to julienne into thin slivers.
When fish is finished, remove the dish from the steamer and pour the accumulated cooking liquid onto a large deep plate for serving. Top the ginger slivers and the chives over the fish.
In a small frying pan, heat up the olive oil and sesame oil until just before it begins to smoke, then pour it over the fish. The chives and ginger should sizzle.
Transfer the fish to the plates containing the reserved steaming liquid and serve.