From My Bowl

0 Cook the Pasta: Bring a large pot of water to a boil. Add the salt and pasta and cook until al dente, according to the package instructions. Remove and reserve 1 cup of pasta water when the pasta has 2 minutes left to cook, then, add the spiralized or shredded zucchini (if using) for the final 2 minutes of the pasta cook time. The zucchini will cool the water slightly, so you may need to cook the pasta for an additional minute. Drain and set aside.
1 Sauté the Zucchini: In the meantime, shred the zucchini with a box grater and use your hands to squeeze out any extra liquid. Warm the olive oil in a medium sauté pan over medium heat, then add the shallot. Sauté for 3 to 5 minutes, until the shallot is translucent and beginning to brown. Add the shredded zucchini and mix well; spread the zucchini mixture evenly across the bottom of the pan. Sauté for an additional 6 to 8 minutes, stirring the zucchini only every 2 minutes or so to encourage some browning. Transfer the zucchini mixture to a plate and place in the refrigerator for at least 10 minutes to let it cool to room temperature.
2 Make the Pesto: Add the walnuts, garlic, salt, and chili flakes (if using) to a food processor with a S-blade attachment. Process for 45 to 60 seconds until the walnuts are finely chopped, scraping the sides of the food processor with a spatula as necessary. Add the basil, parmesan, and lemon juice to the food processor and process again until finely chopped. Seal the processor, turn it on, and slowly stream in the olive oil; process for 45 to 60 seconds, until smooth. Add the cooled zucchini mixture to the food processor and process one final time, until a thick and smooth mixture forms; the pesto will have a similar texture to hummus.
3 Combine: Add the drained pasta to the pot or pan you used previously and warm over medium heat; add the zucchini pesto along with 2 to 4 tablespoons of the reserved pasta water. Use tongs to mix well, adding more pasta water as necessary to create a thick sauce. Continue to mix until the noodles are evenly coated.
4 Serve: Divide the pasta among serving plates and serve warm, topped with extra parmesan, chili flakes, basil, or as desired. Store any leftovers in an airtight container in the refrigerator for up to 5 days.