Heat some oil in a wok or large pan.
Add the shrimp and cook until they turn pink and are fully cooked. Set aside.
In the same pan, sauté the sliced red onion until it becomes soft and translucent.
Add the kari leaves and crushed cili padi with ground spices; stir-fry until fragrant.
Pour in 1 tablespoon of salted soy sauce (ketupat) and a teaspoon of tamarind paste. Stir well to combine, allowing the flavors to meld.
Return the shrimp to the pan and toss them in the marinade mixture for about 2-3 minutes or until heated through.
Season with a pinch of salt and serve immediately.