This Thai seasoning paste is used primarily to make the curry dish gaeng mussaman. The combination of spices and fresh seasonings comes from the Indian Muslim cooking influence.
Heat a small frying pan over medium heat.
Add the coriander, cardamon, and cumin seeds with the cinnamon stick, cloves, and peppercorns; gently agitate until the spices are aromatic (about 1 min)
Transfer the roasted spices to a mortar, add the nutmeg; grind to a fine powder and transfer to a small bowl
Dry-roast the chillies in the pan until aromatic (about 1 min), then transfer to a mortar and grind finely then add to the other spices
Dry-roast the shrimp paste until aromatic (about 45 seconds), remove from the heat
In the mortar, grind the lemon grass, coriander root, garlic, eschalots, ginger, and galangal to a paste, Add the shrimp paste, lime rind, and salt; grind until well mixed
Add the ground spices; grind to a smooth paste and refrigerate in an airtight storage container for up to 1 week