Because they use modernist ingredients, these amounts are given in metric by weight. For more information on how to measure modernist ingredients check out this article.
Mix all of the ingredients together in a small bowl until thoroughly combined.
Coat the pork shoulder with the spice rub, being sure to rub it into the sides.
Heat oil in a pressure cooker over medium-high heat. Sear the pork shoulder until browned on all sides. This can be done in batches if there isn't enough room in the pressure cooker. Remove the meat from the pressure cooker.
Add oil to the pressure cooker along with the onion. Cook until softened, about 5 minutes. Add the garlic and cook another 2 to 3 minutes. Add the pork back to the pressure cooker, settling it into the onion and garlic mixture. Add enough chicken stock and water to raise the total depth to about 2" to 3" (50mm to 75mm).
Seal the pressure cooker, bring to full pressure, and cook for 75 to 90 minutes. Remove from the heat and let it depressurize naturally. Take the pork out of the pressure cooker and pull it apart using a fork. Process the liquid and vegetables in the pressure cooker using an immersion blender. Return the pulled pork to the pressure cooker until ready to serve.
Combine 150g pineapple and 10g serrano chile with all the lime juice and olive oil. Blend until the pineapple is broken down and the mixture is smooth. Salt and pepper to taste. Add the xanthan gum and blend to combine.
Place the remaining ingredients in a bowl and pour the dressing over top then mix well.
Add a spoonful of the pulled pork to a bowl, plate, or lettuce cup. Top with the pineapple chutney and cilantro then serve.