Place the pork of choice in a large pot. Add enough water to cover the meat, about 12 cups, and the salt. Bring to a boil over high heat, then reduce heat and simmer for about 1½ hours, or until just tender. As the pork cooks, add more hot water as needed to keep covered.
Preheat oven to broil, with rack placed in the middle of the oven. Line a rimmed baking sheet with foil.
Remove the pork from the liquid, and place it on the sheet. If using the pig’s head, use a knife and carve out as much meat as possible. Let the broth cool and save for another use.
Broil the pork until slightly charred, about 10-15 minutes, watch closely to prevent burning. When the meat is cool enough to handle, chop it into small bite-size pieces.
Melt the butter in a 12-inch skillet over medium-high heat. When bubbling, add the onions and 2 tsp. garlic; cook until onions are soft about 3-4 minutes.
Add the chicken liver; cook, stirring occasionally, for about 2 minutes. Add the chili, chopped pork, soy sauce, vinegar, sugar, and Maggi seasoning; simmer about 10 minutes. Remove from heat and allow to cool overnight or at room temperature until ready to serve.
Heat up a wok or non-stick pan, place 3 tsp. of chopped garlic and cook till lightly browned. Add in the rice and pork sauce mixture and sauté until combined. Remove from heat and serve in bowls with an over-easy egg and pickled red onions.