Fill a large saucepan halfway with water and bring to a boil on high heat. Meanwhile, prepare a medium mixing bowl filled cold water. (Add 2 cups ice to make the water really cold.) This bowl will be used to "shock" your arugula after blanching. Shocking helps maintain the vibrant green color of the arugula.
Add washed arugula or kale in two batches to the boiling water. Submerge in water for 20-60 seconds (arugula/kale) and remove with a slotted spoon. Transfer the hot arugula to the ice water bath and submerge for one or more minutes. Use your hands to squeeze out the water from the arugula and set aside until needed.
to process
In a food processor, add garlic, walnuts, and optional parmesan, and blend for 10–20 seconds. You want it slightly chunky at this point.
Add the blanched arugula. Blend for 10 seconds or so. Add the raw spinach and pulse until the leaves are incorporated.
Add the olive oil, salt, black pepper, and lemon. Blend until fully incorporated. Taste, and make any adjustments you like by adding more salt, lemon, etc.
embellish a pesto pasta with an extra vegetable topping, such as turnips and greens, golden beets, or cauliflower and onion. Cook up a simple sauté, or braise the vegetables in garlic and a bit of water.
My next favorite option is to use the pesto as a spread on toast and top it with a simple poached egg. Perfection.
Or as a base for a pesto pizza. I like pita bread pizzas since they are thin crust, and get nice and crispy in the oven. Try topping the pizza with parboiled potatoes and fresh red peppers, or red onion and yams.