Bring a large pot of water to a boil for the pasta.
Meanwhile, add all ingredients for the pesto in the bowl of your food processor (pistachios; garlic; grated cheese; basil and olive oil). Process until smooth.
Taste and add salt, if needed. Transfer to a bowl and set aside.
For the pasta
Add salt to the pot of boiling water and cook the pasta for 2 minutes less than suggested on the package, until very al dente.
While the pasta cooks heat olive oil in a large enough skillet to hold the pasta.
Add the remaining minced garlic clove and the shrimp. Cook the shrimp for a minute on each side. Do not overcook! Transfer to a plate.
Pour the pistachio pesto into the same pan. Add a ladle or two of starchy pasta water to thin out the sauce. The sauce will have a creamy consistency.
Drain the pasta, reserving some of the pasta water, and add to the pan with the pesto. Stir to combine the pasta with the pesto. If needed add extra water and cook, stirring, until the pasta reaches the desired level of doneness.
Toss the reserved shrimp back into the pan and drizzle a little extra olive oil over the dish.
Serve immediately topped with chopped pistachios to garnish.
Notes
Substitutions and Variations:-If you're not a fan of pistachio pesto, try this recipe with basil pesto instead. -For a dairy free version of this recipe, omit the grated Pecorino Romano cheese from the pistachio pesto. -For a vegetarian version, omit the shrimp and simply serve the pasta with pistachio pesto. Or try adding sautéed or grilled vegetables instead! -Try adding a few sprigs of parsley along with the basil to your pesto.Which pasta shapes work well in this recipe?-I made this dish with linguine as I enjoyed in Sicily, however just about any pasta shape will do such as spaghetti; bucatini or even shorter pasta such as penne or fusilli.Tips:-Adding pasta cooking water to the pistachio pesto as well as when tossing in the pasta at the end of cooking is crucial for several reasons: it helps thin out the sauce; the starch in the water gives the pesto a creamier texture and helps adhere the sauce to the pasta. Do no skip this step! -In order to prevent the shrimp from overcooking, remove from the pan before adding the pistachio pesto and pasta. Stir them in at the end, just before serving. -If you prefer smaller pieces of shrimp distributed in your pasta, cut the shrimp into bite sized pieces.Storage:-This pasta is best eaten immediately, however if you happen to have any leftovers they may be refrigerated for up to 2 days.Please note that the nutritional information provided is approximate and may vary according to exact ingredients and portion size.