This pasta dish is modeled on the spaghetti al pesto di limone that Giovanna Aceto made for us on her family’s farm in Amalfi, Italy. The lemons commonly available in the U.S. are more acidic than Amalfi’s lemons, so to make a lemon pesto that approximates the original, we use a little sugar to temper the flavor. For extra citrus complexity, we add lemon zest to the pasta cooking water; the oils from the zest lightly perfume the spaghetti, reinforcing the lemony notes of the pesto.
Notes
Don’t forget to remove the lemon zest from the boiling water before dropping in the pasta. If left in as the spaghetti cooks, the zest may turn the water bitter, and the strips are a nuisance to remove from the strands of cooked noodles.
Ingredients
- 4 lemons
- kosher salt
- ground black pepper
- 1 ½ teaspoons white sugar - divided
- 1 pound spaghetti
- ½ cup slivered almonds - lightly toasted
- 1 ounce Parmesan cheese - without rind, cut into rough 1-inch pieces, plus finely grated Parmesan to serve
- ⅓ cup extra-virgin olive oil - plus more to serve
- 2 tablespoons finely chopped fresh chives
Instructions
Perfume the cooking water:
- Using a vegetable peeler (preferably a Y-style peeler), remove the zest from the lemons in long, wide strips; try to remove only the colored portion of the peel, not the bitter white pith just underneath. You should have about ⅔ cup zest strips.
- In a large pot, combine 2 quarts water, 1½ teaspoons salt, 1 teaspoon of sugar and half of the zest strips.
- Bring to a boil and to cook for 2 minutes, then remove and discard the zest.
Cook the pasta:
- Add the spaghetti and cook until al dente.
- Reserve 1 ½ cups of the cooking water, then drain the pasta and return it to the pot.
Make the pesto:
- Meanwhile, in a food processor, combine the remaining zest strips, the almonds, Parmesan, the remaining ½ teaspoon sugar and ¼ teaspoon each salt and pepper.
- Process until the mixture resembles coarse sand, 10 to 20 seconds.
- Add the oil and process just until the oil is incorporated (the mixture will not be smooth), about another 10 seconds; set aside until the pasta is ready.
Sauce and serve:
- To the spaghetti in the pot, add the pesto and ¾ cup of the reserved pasta water, then toss to combine; add more reserved pasta water as needed so the pesto coats the noodles.
- Toss in the chives.
- Taste and season with salt and pepper.
- Serve drizzled with additional oil and with additional grated Parmesan on the side.