The walnuts are a more frugal (and more flavorful) option than pine nuts and I love the light lemony flavor the zest provides (the juice was too sharp so save it for another use). A quick blanch in salted water for the kale is the only cooking this pesto requires so it’s perfect for an end of summer meal. Then, use the same salted water to cook your pasta in afterwards – don’t mess with two pots!
Bring a large pot of salted water to a boil. Meanwhile, prepare an ice bath by filling a large bowl with ice water. Leave enough room in the bowl to add the kale later.
When the water is rapidly boiling, add the kale and blanch for 45 seconds.
Using tongs, remove the kale and plunge it immediately into the prepared ice bath to stop the cooking process. (If you are serving this with pasta, add the pasta to the boiling water now.)
Once the kale has cooled, remove it from the ice bath and squeeze out as much liquid as possible. Be sure to squeeze out as much as you can, otherwise your pesto will be too watery.
In a food processor, pulse the squeezed kale until it is roughly chopped (3-4 pulses).
To the food processor, add the lemon zest, grated garlic, walnuts, parmesan and salt. Process until a coarse paste results.
Open the feed on the food processor. With the processor running, stream in the olive oil.
Add more salt to taste.