First, make the pasta sauce. Place the cashews, beans, lemon juice, paprika, turmeric, miso, nutritional yeast, garlic, cayenne, and water into a blender or a food processor and blend/process until totally smooth. The sauce should yield about 1 1/2 cups. Set it aside until you're ready to use it.
Bring a pot of salted water to boil and add the pasta. Cook the pasta, stirring frequently, until the pasta is tender, using the package instructions to help inform cooking time.
Drain the pasta and return it to the pot. Add the cooked peas. Add the sauce and fold everything together gently, until the pasta dish is creamy and evenly coated. Adjust seasoning to taste. You may not need to use all of the sauce -- if you have a few tablespoons leftover, you can reserve them as a dip or a dressing for a salad or a grain bowl, or you can use them to top leftovers. I usually use the whole batch, but sometimes I end up having a small amount leftover.
Divide the mac n' cheese onto four plates or bowls and serve. Leftovers will keep for up to three days in an airtight container in the fridge.