In a medium saucepan combine potato, carrot, onion, cashews, and 1 cup of water.
Bring to a boil, lower heat and simmer covered for 15 minutes.
Remove from heat and allow the vegetables to cool a bit. Do not drain.
While vegetables are cooling, cook pasta according to the package directions.
Once the vegetables have cooled, pour them into a blender or food processor along with the remaining water that’s in the pan.
Add the salt, garlic, Dijon mustard, lemon juice, black pepper, paprika, and cayenne and blend.
Add ½ cup of water and blend until completely smooth. Add more water if needed, for a thinner consistency.
Add additional salt and/or lemon juice to taste.
Toss with hot pasta and enjoy.
