Cook the bacon in a large pot over medium heat for 7 minutes until browned but not brittle.

Add the onion and cook in the bacon fat for 5 minutes until translucent.

Stir in the green beans, broth, salt and pepper and bring to a simmer.

Cover partly and cook for 35 to 40 minutes, stirring twice, until the beans are tender and the broth has reduced to a few spoonfuls.

Stir in the vinegar and cook uncovered for 2 minutes before serving.