Grilled Pork Skewers

Name: Grilled Pork Skewers
Ingredients: 1/2 pound boneless pork shoulder; 1/2 pound pork belly; 1 head garlic, about 8 cloves, minced; 1 cup soy sauce; 1 cup banana ketchup or tomato ketchup; 1 (12- ounce) can lemon-lime soda, like 7-Up or Sprite; 1/4 cup calamansi or lemon juice, fresh or frozen concentrate; 1 teaspoon toasted sesame oil; 1 teaspoon garlic powder; 1 teaspoon red pepper flakes; 1 pinch salt; 1/4 teaspoon ground black pepper; 1/2 cup brown sugar; Steamed rice, for serving, optional; Achara, (green papaya pickles), for serving, optional