Directions:

• Place pork, skin side down, in a large Dutch oven. Add lemongrass, bay leaf, vinegar, and enough water to just cover the pork. Bring to a boil over high. Reduce heat to medium, and simmer, covered, until skin can easily be pierced with a fork, about 1 hour and 20 minutes. Remove from heat; transfer pork, skin side up, to a wire rack set inside a large rimmed baking sheet. Chill in refrigerator, uncovered, until cooled, about 1 hour.
• Preheat oven to broil with rack positioned about 6 inches from heat. Remove pork from refrigerator, and broil, rotating baking sheet every 5 minutes, until skin is crispy and browned, 15 to 20 minutes. Let pork cool completely on baking sheet, about 20 minutes. Finely chop pork into small (about 1/4 inch) pieces.
• Combine pork, onion, garlic, ginger, and chiles in a large nonreactive bowl. Stir in crumbled liver spread. Stir in Maggi seasoning and 2 tablespoons lime juice; cover and chill in refrigerator for at least 30 minutes or up to 1 day.
• Stir together mayonnaise, ketchup, and sriracha in a medium bowl. Set aside.
• Heat 2 teaspoons oil in a large cast-iron skillet over high. Add half of the pork mixture (about 3 1/2 cups), and spread in an even layer. Season with 1/4 teaspoon garlic salt and black pepper to taste. Cook, undisturbed, until fragrant, about 1 minute. Continue cooking, vigorously chopping and tossing sisig using a metal spatula, until pork is very finely chopped and starts to brown and aromatics are fragrant, 4 to 5 minutes. Drizzle with 3 tablespoons spicy mayonnaise and 1 tablespoon lime juice. Remove from heat, and stir until well combined.
• Transfer sisig to a serving platter or individual plates. Wipe skillet clean, and repeat process with remaining pork mixture, garlic salt, black pepper, spicy mayonnaise, and lime juice. Serve hot with lime wedges, additional sliced chiles, rice (if desired), and remaining spicy mayonnaise on the side.