In a large pot of well-salted water, boil your pasta per package instructions. Reserve 1/3 cup of the pasta water, and drain the rest.
In a large bowl, toss the pasta with the pesto (adjusting with more or less depending on your preference), adding a splash of the reserved pasta water. Add the kale and green onions, toss well, and season with salt and pepper. Serve topped generously with toasted pumpkin seeds, and lots and lots of lemon zest.
Serves 2 - 4. Two if you're hungry w/ a sizeable appetite, more if its part of a larger offering.