Finely chop the onion and brown it well but thinly in a little oil in a frying pan.
Wash and cut green beans in half. Add them to the onion, stir well, cover and let cook about 15 minutes.
Uncover the skillet and put in the meat. Salt moderately and let it cook about 5 minutes, stirring occasionally.
Serve immediately with fleur de sel and ground pepper.