It's this one.

There are separate stovetop and pressure cooker instructions, with the latter using half as much water, though both use 4 cups stock.

However, there are some issues in the comments. One comment asked "Is anyone able to clarify that for the pressure cooker, it's 4 cups of broth PLUS another cup of water? I interpreted the instructions this way and after 40 minutes high pressure and 15mins depressurization there was far too much water, trying to 'mash' with a potato masher was impossible because it was like a big pot of watery soup..."

I'm guessing there's a goof in the recipe, because Instant Pot's recipe for farro calls for 2 cups of water for 1.5 cups of farro--though that's for cooked farro, not a porridge, so 4 c stock alone could be enough to make porridge.

Any thoughts?