Cube up your pork into 1 - 2 " cubes. I had the butcher shop cut it up into cubes and debone it, but when I got home, their cubes were massive, so I cut them up into smaller sizes. But yeah, have your butcher shop do most of the work!
Put pressure cooker pot on stove top, set to medium heat and add oil. Sautee pork cubes so they are browned. You might need to do this in batches or partly in the pressure cooker and the rest in a saute pan.
Cut up onion into chunky chunks and sautee in pressure cooker pot.
Dump all beef stock, pork, onions, cumin, bay leaf, cinnamon stick and any other spices you want to add and beef stock into pot. Attach lid and 'activate' according to manufacturer's instructions. Again, with my ghetto-pot, that means I wait until the stupid knob starts wobbling.
Once wobbling (or 'pressure reached') commences, allow to cook for 45 minutes. Do 'quick release' according to your pot's instructions (for mine, that means running it under the sink).
Remove delicious flesh from pot with slotted spoon; don't forget to throw out the cinnamon stick and bay leaf. It should be SUPER tender and falling apart when you poke at it. Put in container, use two forks, shred apart. Sample copiously, as once it is served, you probably won't have leftovers. I didn't. I'm pretty bummed. Everyone at ALL of it!