In a medium pot over medium-high heat, cook the pasta according to the directions on the package.
While the pasta cooks, add the pistachios to the bowl of a food processor or high-powered blender and pulse until the nuts are broken down.
Add the avocados, basil, garlic, cumin to the bowl of the processor and wiz it on high. While the pesto is forming, slowly add the oil to the mix. Stop and scrape down the sides and taste. Add any salt or pepper at this time.
Drain your pasta, reserving 1 cup of the pasta water. Add the pasta and pesto in a large mixing bowl and toss around. Use the pasta water to thin out the pesto. A drizzle of fresh lemon juice, a little more salt and pepper to top it off.
If you don’t have any fresh basil on hand you can use other fresh herbs like cilantro, but it will have a different flavor profile.
Consider freezing the pesto sauce in cubes if you aren’t planning on using it while it’s fresh.
Reserving the pasta water really helps create a very creamy sauce for your pasta.