Bring water to the boil, then cook the egg for 6 mins take out of the pot and cool down. Peel them.
In a medium-sized pot, place the onions and cover them with water and season with a pinch of salt. Cook over medium to soft texture. Remove from the pot and peel, cut in half.
Cut the halibut in 4 pieces of 150 gr each.
Prepare the steamer, season the halibut with salt and cracked fresh pepper, then steam for 4 mins. Check the firmness of the fish before removing, if needs it leave a further minute but keep in mind that the fish needs to rest for 3 mins so the temperature will increase.
Cut the egg in half serve with the fish, garnish with the half onion two and chervil and drizzle olive oil.