Soak the bamboo skewers in water for at least 1 hour.
Marinate pork at least for 6 hrs. to overnight.
Put the soaked glutinous rice on cheese cloth with one pandanus leaf (Optional), heat in the steamer for 25 minutes.
Prepare the marinate by dry roasting coriander seed in a pan until fragrant and ground together with palm sugar, coriander root, garlic and pepper together. Mix the paste with chili flake, oyster sauce and coconut milk.
Cut pork into small pieces and pour in the marinate, put corn starch. Leave in refrigerator for 6 hrs. to overnight for better taste.
Put marinated pork onto skewers.
Heat grilled pan or oven, then grill them until cook well.
To make a sauce, heat tamarind paste, fish sauce. palm sugar with 1 tablespoon water together, add chili flake, shallot, spring onion and roasted rice.
Serve pork skewer with sticky rice and spicy tamarind sauce.