First, slice and soak the dry red spur chilies in water for about 10 minutes. This softens them for easier pounding, but note that it may reduce the paste's shelf life. Remember to store the finished paste in the fridge or freezer.
Slice the galangal, lemongrass, dried chilies, shallots, and garlic into thin slices.
Lightly toast the coriander seeds and cumin in a skillet over medium heat for approx 30 seconds.
Pound the dry ingredients first: the galangal, salt, toasted coriander seeds, cumin, and lemongrass until they form a coarse mixture.
Add in the remaining ingredients and continue to pound until you get a smooth paste.