Slice the onion thinly and trim the root of the shimeji mushrooms, separating them.

Cut the salmon into thirds. Season with salt and pepper, then coat lightly with flour.

Heat half the vegetable oil in a pan over medium heat. Add the salmon and cook until golden on both sides. Remove and set aside.

Wipe the pan clean with a paper towel. Add the remaining vegetable oil and heat over medium. Sauté the onion until softened, then add the mushrooms and cook for 2 minutes.

Add the soup base ingredients (cream corn, water, milk, salt, consomme) and mix well. Return the salmon to the pan, bring to a boil, cover, and simmer on low heat for 5 minutes, stirring occasionally. Add butter and mix.