1: Prepare 800 g mushrooms (oyster mushrooms): trim off the stalks if necessary, then brush rapidly under running water if they are at all dirty. Cut into pieces and dry.
2: Coarsly chop the parsley leaves. Prepare and finely chop 1 onion (small).
3: Melt 50 g butter in a frying pan on high heat, When good and hot add the chopped onion, salt and pepper. Cook for 1 minute without colouring.
4: Add the mushrooms...
5: ...and cook, stirring frequently.
6: Salt and pepper at the end of cooking, then take off the heat and add the chopped parsley and lemon juice.
7: Mix well and it's ready.
Remarks
Of course, you can use other mushrooms instead of the oyster mushrooms. It is worth using clarified butter in stage 3 as it fries better without burning.