Bring a large pot of water to a rapid boil and season generously with salt (about 4 quarts of water, 2 tablespoons salt). Add your veggies and boil/blanch them until tender, about 5 minutes. Use a fine mesh strainer or tongs to remove the veggies from the pot and transfer to a high-speed blender.
Add your pasta to the boiling water and cook according to the package instructions. Add spinach in when the pasta has about 1 minute left to cook, submerging it in the water. Reserve about ½ cup pasta water, drain, and set aside.
Into the blender with the veggies, add sunflower seeds, hemp seeds, miso, oil, lemon (start with 2 tablespoons), ¼ cup pasta water, salt , nutmeg, and garlic. Blend until smooth. Taste and add more salt or lemon, if needed. If too thick, blend in more pasta water (or tap water).
Transfer pasta pack to the pot, add the sunflower sauce, and toss to coat. If there is extra sauce, save it for topping leftovers.