Place the stock, butter, and salt in the electric pressure cooker and turn on the sauté function. Allow butter to melt and mixture to simmer, approximately 5 minutes.

Stir in polenta and whisk constantly for 2 minutes.

Secure the lid and cook on high pressure for 8 minutes. After cooking, let the pressure release naturally for 20 minutes then quick release. Unlock and remove the lid.

Whisk polenta and stir in parmesan, crème fraiche, and black pepper. Continue to whisk together until cheese has melted and polenta smooths out a bit, approximately 1 minute.

Transfer to a serving dish.