For the clams:

1. Combine the Assam Sambal and clams in a covered wok or heavy pot with a lid and bring to a boil over high heat.
2. Steam until all the clams are just opened.
3. Discard any clams that don’t open.
4. Transfer the clams to a serving bowl and reduce the sauce until thick and chunky, 2 to 3 minutes; pour over the clams.
5. Garnish with the cucumber andlaksa leaves and serve.

For the Assam Sambal:

1. Preheat the oven to 350°F. Spread the dried red chillies on a baking pan and roast until darkly toasted, about 5 minutes. Transfer to a small bowl.
2. Bring the water to a boil in a wok and pour just enough water over the chillies to cover them. Soak for 30 minutes, then puree in a blender or food processor using all the soaking liquid. Set aside.
3. Heat the oil in a heavy pot over medium heat. Add the Balichão and break up using a wooden spoon, cooking until the Balichão turns deep purple in color, about 1 minute.
4. Add the onions and stir, cooking until they begin to caramelize, about 3 minutes.
5. Add the garlic and cook until fragrant, about 30 seconds.
6. Add the reserved chilli puree and tomato paste and slowly work into the oil, letting the pastes bloom and the oil separate out, essentially frying the pastes, about 5 minutes.
7. Add the soy sauce, tamarind, and palm sugar and stir, cooking until the sugar is dissolved, about 60 seconds.
8. Add the cane vinegar and salt, stir to combine, and simmer until the sauce is thick. Remove from the heat and cool. Store refrigerated for up to 1 month if not using immediately.