Let's start with the mushrooms. In banks, they are a little bland. I bring them "to mind". Add salt and a little vinegar to the jar, so that they look more like pickled ones.
Now finely chop the onion, pour boiling water over it to remove excess bitterness. If desired, you can pickle.
We throw the red beans in a colander to drain the juice.
Cut the ham into strips. Cheese can be rubbed on a coarse grater, or you can also use straws.
Cut the parsley.
Now we filter the mushrooms. While everyone was cutting, they picked up acid.