Crush the spice mix (garlic, coriander seeds, and coriander root) with a granite mortar and pestle.
3 cloves garlic, 1/2 teaspoon coriander seeds, 2 coriander root
Add palm sugar, golden mountain sauce, oyster sauce, and fresh milk, and stir everything into one sauce.
1/2 tablespoons palm sugar, 1 tablespoon golden mountain sauce, 1 1/2 tablespoon oyster sauce, 3 tablespoons milk
Transfer the marinade sauce to a large mixing bowl, add pork, and thoroughly coat it with the marinade. Let it rest for at least 4 hours in the fridge or overnight for the best flavor.
1.5 lb pork
Grill your Thai marinated pork over charcoal until thoroughly and evenly cooked through, with a charred crust and tender meat. The grilling time depends on the thickness of your meat and the heat of the charcoal. Occasionally flip to prevent burning.
Let the grilled meat rest for a few minutes to redistribute the juices, and then slice it thinly. Serve immediately with rice and the optional dipping sauce.