Directions

1. Using a vegetable peeler, remove the outer peel (not including the white pith) from 2 of the lemons, in long, wide strips. Set aside. Using a microplane or citrus zester, zest the remaining 2 lemons. Set aside.
2. In a large pot, combine 2 quarts of water, 1 1/2 teaspoons salt, 1 teaspoon of sugar, and the long, wide strips of lemon peel from 2 of the lemons. Bring to a boil and cook 2 minutes. Remove and discard the lemon peel.
3. Add the spaghetti and cook until al dente. Reserve 1 1/2 cups cooking water. Drain pasta and return it to the pot.
4. Meanwhile, in a food processor, combine the lemon zest from the other 2 lemons, pistachios, 1/2 teaspoon sugar, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Process until coarse sand, 10-20 seconds. Add the oil through the feed tube and process until oil is incorporated, about 10 seconds (you are not trying to get the lemon pesto smooth).
5. In the pot with the spaghetti, add the lemon pesto and 3/4 cup cooking water to the spaghetti. Toss to combine. Add more pasta water as needed so the pesto coats the noodles.
6. Divide the pasta into 4 bowls, top each bowl with 1 tablespoon of basil, 1 tablespoon of Parmesan cheese and squeeze of lemon wedge.

Tip: Put the remaining zested lemons back in the fridge or juice the lemons and store in a jar in the refrigerator for another use.