- 3 pounds fresh string beans, trimmed
- 2 cups red onions, thinly sliced
- 1/4 pound prosciutto di Parma, thinly sliced and cut into long, thin strands
- 3/4 cup extra-virgin olive oil
- 6 tablespoons fresh lemon juice (from 2 lemons)
- 1 tablespoon fresh rosemary, coarsely chopped
- 2 teaspoons kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1 teaspoon red pepper flakes
- Stack several slices prosciutto and slice into long, thin strands no more than 1/8-inch thick.
- In large pot of boiling salted water, cook beans until crisp-tender, 2 to 3 minutes. Drain in colander, then immediately transfer to bowl of ice and water to stop cooking. Drain and pat dry. Refrigerate 1 hour, or overnight.
- One hour prior to serving, in large bowl, combine beans, onions, prosciutto, olive oil, lemon juice, rosemary, salt, pepper, and red pepper flakes. Toss gently and let stand at room temperature for one hour before serving.