Preheat oven to 375°. Spread nuts out on a baking pan and bake until golden under skins (break one to test), 10 to 15 minutes. When nuts are cool enough to handle, rub in a kitchen towel to remove as many skins as possible. Chop coarsely and set aside.
In a 4- to 6-quart pot over high heat, bring 3 quarts salted water to a boil. Add green beans and cook until just crisp-tender, 4 to 7 minutes. Drain in a colander and plunge beans into a bowl of ice water to cool. Drain again and set aside.
In a small bowl, stir together the mint leaves, lemon peel, lemon juice, and salt to make the dressing. Drizzle in the hazelnut oil, whisking constantly.
In a large bowl, gently toss the beans with dressing and hazelnuts. Serve at room temperature.
Note: Nutritional analysis is per serving.
Wine pairing: A slightly oaked version of Sauvignon Blanc