Remove any large unwanted sections of fat (this cut has a high fat content therefore only remove fat from the outer layer). Cut pork into roughly 2-inch size cubes. Place the pork in a dutch oven, or deep skillet.
Add garlic, salt, chili, 2/3 of lime juice, and pour stock over the pork until it is just covered by the liquid. Place the dutch oven or deep skillet over medium-high heat and bring to a boil. Reduce the heat to medium-low, and simmer for about 2 hours, uncovered.
Stir pork once after about 1 hour, and check to make sure there is still liquid in the cooking vessel.
While the pork is simmering, in a large mixing bowl, add slaw, cilantro, corn, scallion, 1/3 lime juice, mayonnaise, pepper, and vinegar.
Increase the heat to medium-high, stirring and turning the pork occasionally for about 45 minutes longer, until the liquid completely evaporates.
Stir pork in rendered fat for about 2-3 minutes, until it browns around the edges. Serve the pork in large pieces or shred the pork with hands or a fork removing large pieces of fat.
For each taco layer a tortilla with cheese, pork, and slaw mixture.