To make Pistachio Pesto, start by filling a small pot with water and bringing it to a boil. Add the shelled pistachios and cook for 1 minute to soften the skins. Drain the pistachios, transfer them to a bowl with cold water and ice for a few minutes, then drain again. Rub off the skins with a clean kitchen cloth.
Place peeled pistachios, lemon zest, almonds, garlic, Parmesan cheese, and basil into a small food processor. Pour in the warm water and blend until smooth, gradually drizzling in the extra-virgin olive oil. Adjust seasoning to taste.
Bring a large pot of lightly salted water to a boil, then add the pasta and cook according to the package directions.
Drain the pasta 2 minutes before the suggested cooking time. Reserve 2 tablespoons of pasta cooking water.
Transfer the drained pasta to a large bowl and toss it with the Pistachio Pesto, adding a splash of reserved pasta water as needed for a creamier texture. Finish with chopped sun-dried tomatoes and a sprinkle of freshly cracked black pepper, if desired. Serve immediately.
