Heat a small skillet over medium heat. Add coriander seeds and peppercorns; toast until fragrant, 1 to 2 minutes. Transfer to a spice grinder; pulse until finely ground.
Place pork ribs in a shallow baking dish. Rub ground coriander, peppercorns, and salt over the pork. Cover with plastic wrap and let marinate in the refrigerator, 3 hours to overnight.
Combine palm sugar and 1/4 cup water in a small saucepan over medium heat; cook until sugar dissolves and turns golden brown, 8 to 10 minutes. Immediately stir in sweet soy sauce, lime juice, shallots, fish sauce, and garlic. Simmer until sauce thickens enough to coat the back of a spoon, 5 to 10 minutes.
Preheat oven to 350 degrees F (175 degrees C).
Uncover pork ribs and pour in enough water to almost cover them.
Bake in the preheated even until ribs are tender, 1 to 2 hours. Cut between the bones to separate the individual ribs. Gently toss with glaze and garnish with fresh cilantro.
