In a blender, add avocado (except extra 1/2 - 3/4 cup), potato, lemon, tahini, miso, garlic, salt, mustard, maple syrup, and water. Puree until very smooth. Add the basil and zest and pulse through. Set aside until pasta is cooked. When ready to serve, cook dry pasta (about 1 lb), according to package directions. Drain, and then add back to your pot along with the pasta sauce. Gently heat sauce through with pasta for a minute or two over low-medium heat. If pasta is too thick or dry, add another splash of water. Just before serving, add optional extra avocado and toss through. Taste, and add additional salt or pepper as desired. Serve immediately, garnishing with extra fresh basil, and serving with coarse salt and lemon wedges. Serves 4-5.