To make the Seasoning Paste, grind the chilies, shallots, garlic and black bean paste to a smooth paste in a mortar or blender, adding a little water if necessary to keep the blades turning. Set aside.
Bring the water and 1 teaspoon of the salt to a boil in a pan. Add the beehoon and cook until al dente, about 2 to 3 minutes. Drain and set aside to cool.