Stem the chile and shake out most of the seeds. Chop and place in a bowl of warm water. Let soak for 15 minutes. Place coriander seed in dry skillet and roast for 3 minutes. Remove to a small bowl and do the same to the cumin. Combine the roasted spices and grind to a fine powder. Stir in turmeric and set aside. Place lemongrass and ginger in food processor and process for 3 minutes. Drain chiles and add them and the salt to the processor. Process to a paste. Add garlic, shallot, ground spices and shrimp paste. Process to a smooth paste.