Prepare a steamer over medium heat. Fill it with water and cover the lid. Let it come to a rolling boil.
Marinate the fish with salt in 3 parts - 0.5 tsp on each side, and the stomach, spreading it evenly through the scores and all over the fish.
Place the fish on the steaming plate. Sprinkle the sliced mushrooms all over the fish. Add 2-3 pieces into the stomach.
Carefully place the steaming plate into the steamer once the water is boiling vigorously. Cover the steamer and let the fish steam for 5 minutes.
Next, mix 80ml of water, light soy sauce, and sesame oil in a measuring cup. Set it aside.
After 5 minutes, open the cover. The fish should have changed colour, and there should be some liquid released by the fish. With a steam clamp, carefully remove the steaming plate from the steamer. Drain the fishy liquid into another bowl, and place the steaming plate back in the steamer.
Slowly pour the mixed sauce all around the fish and in between the crevices.
Sprinkle the ginger strips all around the fish. Cover the steamer and let it steam for 3 minutes
Remove the steaming plate from the steamer and switch off the heat.
Sprinkle the spring onions, chilli strips and carrot strips all over the fish.
In a small saucepan, heat the cooking oil over medium heat for about 2 minutes, or until smoking hot. Switch off the heat, and carefully pour the smoking hot oil all over the vegetables and the fish.
Serve immediately.