1. Place chillies and raw rice in a bowl and soak in room temperature water for 10 minutes to soften. Then drain.
2. Place coriander seeds in a dry pan over medium-high heat and cook for 2 minutes or until fragrant. Transfer to a mortar. Repeat with cumin seeds. Then grind spices to a fine powder using a mortar and pestle or spice grinder. Transfer to a small bowl and set aside.
3. Place softened chillies, rice and 1 tsp salt into a mortar and use a pestle to pound to a smooth paste. Add each of the following ingredients separately, pounding well after addition: lemongrass, galangal, shallots, garlic and kaffir lime peel. Stir through shrimp paste and ground coriander and cumin.
4. Store in the fridge for 2-3 days or freeze for up to 4 months.