Bring a large pot of lightly salted water to a boil.

Wash and snap the ends off. Discard any sickly looking, overly skinny, limp, or yucky-looking beans.

When the water is boiling, briefly boil (blanch) the beans for 2-3 minutes or until you start hearing a popping noise and the beans have turned bright green. Quickly drain and rinse in cold water until the beans have cooled.

Preheat the oven to 400 degrees F.

On a cookie sheet, divide the green beans evenly into 8 piles. Carefully bundle each pile of beans with one slice of bacon and return to the baking sheet. This step can be done up to a day ahead of time.

When the oven is ready, place the pan in the oven and bake for 15-20 minutes or until the bacon is crisp and sizzling. While the bundles are in the oven, melt the butter over medium-high heat in a small saucepan. When the butter is bubbly, add in the onions and garlic and sauté for 2-3 minutes or until the onions are softened and fragrant. Reduce heat to low and add in vinegar, sugar, and salt. Remove from heat and set aside.

When ready to serve, place bean bundles on a serving platter and drizzle with sauce. Serve immediately.