Begin by gently massaging the fish fillets with toasted sesame oil, ensuring an even coating. Sprinkle salt and black pepper over both sides of the fillets to enhance the flavor. Set aside.

Julienne the fresh ginger and slice the onion and carrot thinly. Mince the garlic and shallots (if using).

In a medium skillet, heat olive oil over medium heat. Add minced shallots and garlic, sauté until fragrant. Stir in ginger, followed by soy sauce. Simmer for about 30 seconds.

Layer ginger, onion slices, and julienned carrot over the fish fillets in a steamer. Cover with aluminum foil and steam for about 8-9 minutes until the fish is opaque.

After the initial steaming, pour the aromatic sauce over the fish and scatter scallions on top. Cover again and cook uncovered for another 4-6 minutes.

Plate the steamed fish hot and consider garnishing with fresh cilantro or additional scallions. Serve with steamed jasmine rice.