1. Operation to be done the day before: place the potatoes in a freezer bag, add a little water, remove the air and seal. Place the bag on a plate and cook in the microwave for 15 to 20 minutes, depending on the maximum power.
2. Peel the cooled potatoes and cut them into pieces according to your preference.
3. Drain the green beans.
4. Slice the shallot. Chop the parsley.
5. Mix everything with the oil, vinegar, salt, pepper, and enjoy.