Ok guys. This is one of those recipes where you're going to have to trust your own taste. Make it to your own liking, and the more leafy greens you can find and throw in, the better!
It's best if you can find a variety of greens: kale, chard, parsley, basil, chives, garlic scapes, broccoli leaves, almost anything will work. Just don't throw in lettuce because that would be boring and soggy. If you do use kale or chard, strip the leaves from the tougher stems, and toss the stems (or compost, as I'm now learning!)
Handfuls of your favorite greens, which can include any of the above-mentioned greens
Couple cloves of garlic
Parmesan or Romano, grated
Toast the walnuts lightly in a skillet over medium-high heat. Keep an eye on the walnuts and move them around the pan regularly to barely-toast them, and remove from heat when done. Set aside.
Place the peeled garlic cloves in the food processor, add in the toasted walnuts, and pulse to chop. If they're getting stuck, drizzle in a little olive oil to loosen. Add in the greens, a handful at a time. Drizzle in the olive oil, and add a little salt until the greens, walnuts, and garlic are full blended together, and the sauce is loose enough to spoon over veggies, pasta, or some grilled chicken. Use your own judgement here, and add just enough oil and salt till you're satisfied and proud to show off your awesome alternative-pesto making skills to friends and family!
When using the pesto for pasta, keep a cup of pasta water around, and after the pasta drains, place the pasta in a bowl and loosen the noodles a bit with the pasta water, then toss with the pesto and shave some fresh Romano or Parmesan on top. The pasta water is key here to help spread the pesto-loving to all noodles.