1. In small skillet, cook chopped bacon over medium-high heat until crisp. Remove bacon with slotted spoon and set aside. Add shallot to skillet, and cook 5 minutes. Stir in chicken broth and vinegar, and bring to a boil over high heat; cook 2 minutes. Reduce heat to low, and keep dressing warm until ready to serve.
2. Meanwhile, in large saucepot, bring 4 quarts salted water to a boil. Add green beans and cook 5 minutes, or until vegetables are crisp-tender. Drain well and transfer to a serving dish. Whisk warm dressing, spoon evenly over green beans, then sprinkle with reserved chopped bacon.