Turn your instant pot to Saute and add the oil

Add in your diced sweet potato (see notes), onion, and garlic

Saute for 7 - 10 minutes, stirring to avoid burning, until sweet potato begins to soften. If you want your sweet potato to stay intact, cook less time. I cooked mine longer so that it would fall apart and become part of the sauce once cooked. 

Once veggies have softened, turn your instant pot to OFF

Add in the penne, sage, thyme, vegetable broth, and water

Stir well, and make sure the penne is well submerged in the liquid

Seal the instant pot, and turn to manual, setting the timer for 5 minutes

Once the instant pot comes to pressure, it will count down the five minutes. 

Once the five minutes is up, do a quick release

After the pin drops, safely remove the lid

Stir in the heavy cream and parmesan

Let sit a few minutes, stirring, and it will continue to thicken

Add in the chopped spinach until wilted, then salt and pepper to taste

Serve topped with additional freshly grated parmesan cheese