1. Steam green beans, wash vegetables.
2. In a saucepan with boiling salted water, pre-bean green beans and potatoes for about 10 minutes.
3. In a skillet, pour the oil and fry the mushrooms for about 2 minutes.
4. Add the drained potatoes and green beans and cook over medium heat for about 7 minutes.
5. Salt, pepper, add some berries and chervil and cook for another 4 minutes.