Welcome to Cooking Without Recipes, in which we teach you how to make a dish we love, but don’t worry too much about the nitty-gritty details of the recipe, so you can create your own spin.
This is what you make when you swear you have nothing in your fridge. That’s okay, since you have what you need in your pantry. It also alleviates that home-late-from-work-and-starving panic, in that this dish comes together in the time it takes to cook the pasta (and you can snack on the untoasted walnuts while you wait). I’ve tried it with just about every almost-empty bag and box of pasta that’s sat on my middle shelf, and I found that I like this best with whole wheat spaghetti. Something about the grainy nuttiness of the pasta works well with the grainy nuttiness of the pesto. Bonus: If you have some ricotta in your fridge, a dollop on top is pure luxury.
Measure about 3.5 ounces of whole wheat spaghetti per person. Bring a pot of salted water to a boil. Meanwhile, toast a cup of walnuts either in a 350° oven or a dry skillet over medium heat until you can smell them—that’s when you know to stop. (Confession: Sometimes I don’t even toast the walnuts.)
Use a mortar and pestle to crush half a garlic clove with a big pinch of kosher salt. Add the walnuts, some sage—about three fresh leaves or two generous pinches dried—and crush until chunky-creamy. Drizzle in a quarter-cup of olive oil. Season to taste, adding grated Parmesan if you’d like.
Cook the spaghetti until al dente, reserving a half-cup or so of the pasta cooking liquid. Stir the cooking liquid into the pesto to thin it out a bit—you want it silky with chunks. Toss the pasta with pesto in a big bowl and season with salt and pepper to taste. Top with more grated Parmesan and Microplaned lemon zest.