1) Shell pistachios. If you have any stubborn ones, you can use a half shell from another pistachio to pry open the shell.
2) Add nuts to a food processor with basil, mint, and minced garlic. Drizzle in a few tablespoons of olive oil and pulse until the mixture is a coarse paste.
3) Drizzle in rest of olive oil until pesto is a good consistency. There shouldn’t be any lumps, but it doesn’t need to be completely smooth.
4) Remove pesto from food processor and season with salt and pepper. Stir in minced scallions and Parmesan cheese.
Store pesto in the fridge for up to five days.
To use it in pasta, it’s best to warm it in a pot with some hot pasta water to loosen it a bit. Then stir that mixture into the hot pasta.