Add all the ingredients to the inner pot. Stir to mix. Close and lock the lid, turning the steam release valve to closed.
Set for 3 minutes on Steam (high pressure.) Allow for a full NPR. This will take about 45 minutes because the pot is so full.
After the pressure is completely released, carefully open. It will be quite frothy and bubbly inside, so be careful! With a silicone whisk, stir until any remaining chunks are lifted from the bottom and mixed completely smooth.
Allow to cool a bit with the lid off before serving. Leave on Keep Warm. Store any leftovers in the refrigerator.
Notes
Use high quality, full fat milk and cream for the creamiest and thickest results
Use good quality chocolate chips (I use Ghiradelli brand chips)
This is rich, so even 4 ounces would be good for a serving.
Remember, it's Christmas. The calories don't count. ;)