Bouneschlupp (green bean soup)

Instructions

1. Peel the potatoes, dice them, and thinly slice the onion and the white of the leek. Top and tail the green beans, then cut them into pieces.
2. Melt the bacon with the butter in a large saucepan over medium heat for 3 minutes, until it renders its fat and starts to brown.
3. Add the onion and leek, cook for 5 minutes without browning, then sprinkle with flour and stir for 1 minute.
4. Gradually pour in the stock while stirring to avoid lumps, then add the potatoes. Bring to a boil, then simmer for 15 minutes.
5. Stir in the green beans and keep simmering for 25 minutes, until the beans are tender but still green.
6. In a bowl, whisk the yolks with the crème fraîche. Off the heat, whisk a ladle of hot broth into this mixture, then pour everything back into the pan.
7. Season with salt, pepper and nutmeg, add the parsley and, if you like, a spoonful of vinegar. Do not let it boil after thickening.
8. Serve piping hot with country bread.