In pressure cooker, elbow macaroni, olive oil, and 4 cups of water to cover the pasta.
Place trivet on top of pasta and set cake pan on top of trivet (see links for product details).
In the cake pan, add cashews, potato, carrots, garlic, butter, & ¼ cup water. Cover with foil.
Add pressure cooker lid, and make sure the vent is closed.
Cook at high pressure for 4 minutes.
Once cook time is finished, do a quick release right away.
Carefully remove cake pan from the pressure cooker and pour all ingredients in pan into your blender. Add all sauce ingredients to the blender and blend on high for about 30 seconds, or until completely smooth.
Add sauce mixture back into the pressure cooker on top of the noodles, and stir. The sauce will be thin at first, but as you stir, it will become a thicker sauce within a few minutes.