Boil water and cook pasta according to package instructions.
While pasta is cooking, add pistachios to a food processor and blend until finely ground.
Add in garlic and seasonings and pulse until ground into the pistachio, scraping down the sides to combine.
Add in basil and parmesan cheese, pulsing until fully ground and incorporated. The mixture should have the texture of a grainy paste.
Add in olive oil and pulse until combined, mixing together by hand if needed.
When pasta is done cooking, turn off heat, reserve up to ¼ cup of pasta water, then drain pasta.
Add the pasta back into the pot and stir in the pesto, mixing in the pasta water in small portions until the pesto has slightly thinned and covers the pasta evenly.
If desired, top with more parmesan cheese, crushed pistachios, and seasonings before serving.