Bring a large pot of water to boil and fill a large bowl with ice water. Once the water is boiling, stir about half of the kale into the pot and let boil for 1 minute to blanch. Remove the kale using tongs or a slotted spoon and place immediately into the ice water to stop the cooking process. Repeat with remaining kale.

Once all kale has been cooked drain well. Then place the blanched kale in a large cotton tea towel or between several layers of paper towels and squeeze out as much of the water as possible.

Place the prepared kale into a food processor along with the pistachios. Pulse to roughly chop. Scrape down the sides.

Add the parmesan cheese, lemon zest and juice, garlic, salt, and pepper into the food processor. Blend until evenly combined but still a bit chunky. Scrape down the sides.

With the food processor running, slowly drizzle in the olive oil until the pesto reaches your desired consistency.

Use the pesto sauce immediately or store it in the fridge for up to 3 days or the freezer for up to 6 months.