Ingredients for 4 servings

servings
  • 500 g (17.75 oz) sweet onions (Roscoff style or from the Cévennes) peeled
  • 50 g (1.75 oz) salted butter
  • 50 g (1.75 oz) flour
  • 2 dl good alcohol or rice vinegar
  • 3 dl prepared beef broth
  • salt and ground pepper.