Pork shoulder is brilliant for batch cooking because it shreds so easily after a long cook. Since you are working with budget pantry staples, you do not need expensive blends. A simple mix of salt, black pepper, garlic powder, dried thyme, and a bit of smoked paprika gives it a deep, savory flavor. If you have a bay leaf or two, throw them in as well.
Add a splash of water or broth to the multicooker so it creates its own juices, set it on slow cook, and let it break down completely. Once done, you can portion it out for the week easily.