In a large pot of salted boiling water, cook beans 3 to 8 minutes or until tender. Drain and place in a large bowl.
Add olive oil, lemon zest, hazelnuts, salt and pepper. Beans may be made a day ahead, chilled and covered. Reheat beans, preferable in a microwave.
Variations: Use toasted almonds instead of hazelnuts and add some lemon juice to the cooking water. Omit the olive oil and substitute a slightly sweet balsamic drizzle sauce when tossing the beans, hazelnut and zest.