Bring a large pan of salted water to the boil. Throw in the beans and let them cook until just tender, 8 minutes is just right for fine beans. Meanwhile simmer the garlic in the crème fraîche in a small non stick pan for about 5 minutes, until the garlic starts to smell fragrant.
When they are ready – I do not think they develop their flavour properly if they are eaten too crisp and raw – drain the beans thoroughly, refresh them under cold water if you want to serve them later and drain again. When you are ready to serve them, toss them in the cream and garlic mixture and heat them up in it. Season with pepper and add salt if necessary. Serve with roast or grilled meat or chicken – such as the poulet au vinaigre.