Blanch the carrot tops. Bring a few cups of water to boil in a medium saucepan. Strip the leafy tops from one very large bunch of carrots (or 2 small ones) until you get about 2 cups. Wash the leaves thoroughly, removing the thick middle stem. Add the carrot tops to the boiling water and cook for 2 1/2 minutes, then immediately drain the leaves and rinse under cold water until no longer hot, or use a slotted spoon to grab the basil from the hot water and transfer them to an ice bath. Dry the carrot tops well before using.

Add the pistachios to a food processor and blitz until in small pieces. Add the blanched carrot tops, garlic, lemon zest, lemon juice, salt, black pepper to taste, and nutritional yeast (if using). Blend until a paste forms, scraping down the sides as you go along.

With the motor running, stream in the extra virgin olive oil to start to form a sauce. Scrape down the sides again, and stream in more oil as needed until you have a smooth yet thick texture. If the pesto is still not smooth enough but you don’t want to add more oil, add a spoon of water at a time until the sauce comes together. Taste for seasonings, adding more salt, lemon, garlic, or nutritional yeast as needed.

Store in an airtight glass jar in the fridge for 5 days, or freeze up to 6 months.