Heat vegetable oil in a wok or large fry pan. Add shallots and stir fry until light golden brown, about 7 to 8 minutes. Remove fried shallots but leave oil in the wok. Set aside.
Add lemongrass, garlic, and chilies. Stir fry for 30 seconds.
Then add cincaluk and continue to stir fry for 2 minutes.
Add pork, sugar, ground pepper, and tamarind concentrate. Stir fry to get the pork coated with the cincaluk.
Pour in water and continue to stir fry for 3 to 4 minutes or until sauce thickens. Turn off stove.
Transfer to a serving dish. Garnish with fried shallots and green onions.
Serve immediately with steamed rice.
Notes
**If you are using asam jawa (tamarind paste), rinse and soak 1 tbsp asam jawa in ½ cup (120ml) water for 5 minutes. Strain and use the juice. Omit ½ cup (120ml) water in Step 5.