Bring a large pot of water to a rapid boil and salt it well. Prepare an ice water bath. Add just enough beans to the water to maintain a boil. Blanch for 1 minute and add to ice bath. Do this in batches until you are done with all the beans. Drain the beans well and put in a serving dish.
Combine onion, mint, champagne vinegar, and olive oil. Season with salt and pepper. Toss to combine and pour over the beans and toss again and serve.
Recipe courtesy of Trey Foshee from George?s at the Cove