Bring a large saucepan of salted water to a boil over high heat. Cook beans in batches until tender. Remove from the water and stop the cooking by placing in a bowl of ice water. Drain and reserve.
Preheat oven to 350˚F. For the prosciutto; lay slices between 2 pieces of parchment paper on a sheet pan. Set another sheet pan on top. This will help the prosciutto to lay flat and cook uniformly. Place in oven and cook for 8-10 minutes until prosciutto is crisp. Reserve.
To make the soffrito, combine the onions, red pepper and olive oil in a small skillet with a pinch of salt. Place over medium heat and cook until vegetables have cooked down and are soft, about thirty minutes serving occasionally.
To serve, heat a large skillet over high heat. Add the soffrito to the pan and the beans. Toss beans with the soffrito and season with salt and pepper to taste. Garnish with crispy prosciutto.
Enjoy with a glass of Cakebread Cellars Cuttings Wharf Chardonnay.