Trofie al Pesto Genovese

Method

1. First make the pesto. Put the basil, pine nuts, garlic clove, and 1/2 teaspoon salt in a food processor and pulse a few times until roughly chopped.

2. Add the grated Parmesan and Pecorino, then with the machine running slowly pour in the olive oil until you have a loose, bright green paste. Do not over-process; a slightly textured pesto is ideal. Set aside.

3. Bring a large 6-quart pot with about 4 quarts of water and 1 tablespoon of salt to a boil over high heat.

4. Add the cubed potato to the boiling water first and cook for 5 minutes, since it takes longest.

5. Add the pasta and the green beans to the same pot and cook everything together according to the pasta package time for al dente, usually 9 to 11 more minutes, so the potato is tender and the beans are crisp-tender.

6. Just before draining, scoop out about 1 cup of the starchy pasta water and set it aside.

7. Drain the pasta, potato, and beans together, then return them to the warm pot off the heat.

8. Spoon the pesto over the hot pasta and add about 1/4 cup of the reserved pasta water. Toss gently until everything is evenly coated in a creamy green sauce.

9. Add a little more pasta water if it looks thick; the sauce should be loose enough to cling but not watery.

10. Taste and add salt if needed, then serve right away with extra grated Parmesan.

Cooking times vary by equipment -- cook to temperature and to taste.