"I hope this walnut and parsley version serves as a reminder that 'pesto' is not a recipe, but a technique. The buttery walnuts temper the fire of the mashed garlic and pair beautifully with the aromatic, bittersweet parsley. Use on toasted bread, pizza or pasta, or on roasted chicken--it's that versatile!"
Place garlic and salt in a mortar; smash and mash with the pestle until it becomes a paste, 5 to 8 minutes. Add walnuts; mash walnuts into a paste until you reach your desired texture (coarse or smoother), another 5 to 8 minutes. Add parsley and mash to break up and blend with the walnut/garlic mixture, about 4 minutes. Add lemon juice and olive oil; stir, mash, and emulsify liquids into the mixture until it becomes very thick and well blended, 8 to 10 minutes. Taste and adjust seasonings. If mixture seems too thick, whisk in a tablespoon of water, or as needed.
Spread on bread, use on pizza or pasta, or on roasted chicken. The taste is just like garlic butter, so use it as such.