Sweet and Sour Green Beans

Cook bacon in a medium skillet over medium-high heat, stirring occasionally, until well-browned. Add onion and cook until translucent. Stir in flour and cook 2 minutes more.

Pour vinegar and 3/4 cup of the reserved green bean liquid into the pan. Add sugar, salt, and pepper, and stir to combine. Bring to a boil, reduce to a simmer, and stir in the green beans. Continue cooking at a low simmer until beans are hot.