Cook beans according to package directions. Meanwhile, in a 6-qt. stockpot, cook bacon over medium heat until crisp, stirring occasionally. With a slotted spoon, remove bacon to paper towels; reserve drippings. , In same pan, saute onions in drippings over medium heat until tender and lightly browned, 7-9 minutes. In a bowl, whisk remaining ingredients until smooth; add to pan. Bring to a boil; cook and stir until thickened, 1-2 minutes., Drain beans and add to warm dressing; toss and heat through. Top with bacon.