Shred apart the maitake mushrooms. Thinly slice the onion.
Lightly season the salmon with salt and pepper and dust with some extra flour (not included in the ingredient list). Pan fry on both sides until golden brown.
Put the butter and a little vegetable oil in a frying pan. Add the onions and stir fry a little, then add the mushrooms and continue stir frying. When the onions and mushrooms have wilted, sprinkle in the 1 or 1 1/2 tablespoons of flour.
If you add the flour after you've stir fried the onions and so on instead of cooking it with butter alone, lumps are less likely to form.
Add the milk and soup stock cube and adjust the seasoning with salt and pepper. Heat until the sauce is just simmering, stir and it's done. Pour over the cooked salmon to finish.
Use less flour if you want a thinner sauce.
I usually make an extra portion of this (salmon and sauce), and use it the next day on pasta for my lunch.
Add the following to the leftover sauce to make the pasta dish:
A little spinach, a little milk, grated cheese, and 1 portion of pasta.
Cook the pasta. In the meantime, flake the salmon and stir-fry.
Thin out the sauce a little by adding milk. (Use cream instead for an even tastier version.)
Season with salt and pepper, and add some grated cheese.
Just before the pasta is done, add the spinach to the cooking water. You can boil it separately if you like.
Mix the cooked pasta with the sauce and it's done.
It's a chore to make this pasta from scratch, but with leftover sauce, you can prepare a lunch for yourself in no time.
Story Behind this Recipe
I always eyeball the ingredients, so I measured them properly for this recipe and uploaded it.
The sauce turns this rather dull grey because of the maitake mushrooms, but if you use other types of mushrooms it will form a nice white sauce. Use soy milk instead of milk for a healthier version.