Drape the bacon in a single layer on the bottom of the Instant Pot. (Slow cooker and oven adjustments follow.) Press the “Sauté” button and in about a minute, the bacon will start to sizzle. Flip the slices as they start to brown, and then turn off the heat when the bacon is browned on both sides.
Meanwhile, cut the pork shoulder into 3 equal pieces. When the bacon is cooked, place the pork over the bacon slices, distributing the pieces of pork as evenly as possible. Add the garlic cloves and quartered onion. Sprinkle the salt evenly over the pork, and then grind the pepper mill liberally overtop. (I use about 1/2-3/4 teaspoon pepper). Pour in the water.
Next, cover and lock the lid. Select the “Manual” button and press the “+” button until you reach 90 minutes. (The cooker defaults to high pressure under the manual setting, so there’s no need to do anything else; but do make sure the vent is closed. Note that the digital readout will say “On” until the pot comes to pressure, at which point the timer will start counting down. Coming to pressure will take 20 minutes, give or take.)
When the pork is finished cooking, the Instant Pot will switch automatically to its “Keep Warm” mode. At this point you can select “Cancel” and allow the pressure to naturally release. This will take 15-20 minutes. Once the cooker is depressurized, check that the pork can be easily pulled apart with two forks. If the meat isn’t yet fall-apart tender (it likely will be), you can cook the pork under high pressure for another 5-10 minutes.
With a slotted spoon, transfer the cooked pork to a large bowl and shred it with two forks. Any fatty pieces will separate easily from the meat at this point and can be discarded. Taste the cooking liquid in the pot (careful – it’ll still be hot), and if needed adjust the seasoning with a little more salt or a bit of water. At this point, you can skim off the fat, if desired, and serve with the shredded meat.
Leftover pork can be stored in an airtight container in the refrigerator for up to 4 days and freezes well.
Easy side dish: Kalua pig is often served with braised cabbage. As an option, you can slice a head of green cabbage into 6 wedges and place them in the cooking liquid after the pork has been removed. Replace the lid of the Instant Pot, return it to pressure under the manual setting and cook the cabbage under high pressure for 2 to 4 minutes, depending on size of wedges and how tender you like your braised cabbage. (Four minutes doesn’t seem long but will yield very tender cabbage.) At the end of cooking time, activate the quick-release valve to release the pressure. Once the cabbage is cooked, mix it into the shredded pork or serve alongside.
Optional methods of preparation:
Slow cooker: Line the slow cooker with the raw bacon. If your slow cooker has a sauté option, you can brown it as in the pressure cooker recipe; otherwise it’s fine to skip this step. Prepare the pork as directed above and place in the slow cooker. Do not add any water. (You’ll still end up with a good amount of broth.) Cook on low heat for 8-10 hours, depending on the size and age of slow cooker. (Newer slow cookers are hotter than older ones and food will generally cook faster in larger models.) Remove the finished pork from the slow cooker. If wanting to serve with optional cabbage, coarsely chop the cabbage and add to the cooker, allowing it to cook while you cool and shred the pork.
Stovetop pressure cooker: Follow the Instant Pot directions, but cook on high heat until high pressure is reached. Then, reduce the heat to low to maintain high pressure for about 75 minutes.
Oven: I have not tried, but I have adapted other slow cooker recipes for the oven, using a Dutch oven or another heavy, tight-lidded pot and an oven temperature of 200°F for low heat and 300°F for high. (For this recipe, I’d add about 2 cups of water.) Another rule of thumb is to divide the amount of hours a recipe needs to cook on low in a slow cooker by 4 and cook for that many hours in an oven set to 325°F. For example, a dish that requires 8 hours on low in a slow cooker will take roughly 2 hours, covered, at 325°F. With any of the cooking methods, the goal is tender meat that can be pulled apart easily with two forks.