Put walnuts in a 10- by 15-inch pan and bake in a 350° oven until golden under skins (break one to check), 8 to 10 minutes. Pour from pan. Increase oven temperature to 500°.
Meanwhile, in a covered 5- to 6-quart pan over high heat, bring about 3 1/2 quarts water to a boil. Stir in linguine and boil, uncovered, until barely tender to bite, 8 to 10 minutes. Drain and return to pan.
Trim ends from green beans; rinse and drain beans. In the 10- by 15-inch pan, combine 1 tablespoon olive oil and green beans; spread level in pan. Sprinkle generously with salt and pepper. Roast in a 500° oven until green beans just begin to brown, 4 to 6 minutes.
In a large serving bowl, combine walnut oil, lemon peel, and feta cheese. Add pasta, walnuts, and green beans; mix gently. Season to taste with more salt and pepper.
Wine pairing: A crisp Sauvignon Blanc or Albariño, with flavors of lemon and minerals, is a spot-on match for the lemon and green beans in the pasta. Pinot Gris brings out the richness of the walnut oil and nuts.
Note: Nutritional analysis is per serving.