1. Wear gloves to protect your hands from burning: Use kitchen shears or a knife to remove the seeds and the tough, dry ribs of the chilies.
2. Put all the chilies in a bowl and soak in room temperature filtered water for 30 minutes.
3. Meanwhile, dry-roast the coriander seeds in a small skillet over medium heat for 3-5 minutes, until toasty and aromatic, shaking the pan often to prevent burning. Set aside.
4. Peel garlic. Peel and roughly chop shallot.
5. Combine shallots and garlic in the skillet and dry-roast over medium low heat until tender and slightly browned, about 5 minutes, stirring often. Remove from pan and set aside.
6. Put the roasted coriander seeds in the food processor with the s-blade. Pulse until well ground.
7. Remove lime peel, then mince the lime peel finely. Remove tough outer leaves from lemon grass, trim the lower stalks and slice finely. Peel and chop the ginger finely.
8. Add the minced lime peel, lemongrass, ginger, shallots, garlic, and shrimp paste to the food processor.
9. Drain the chilies, reserving about 1/2 cup of the soaking liquid. Add the chilies to the food processor.
10. Process the ingredients until a rich, moist paste forms. Stop occasionally to scrape down the sides of the work bowl. Add a few tablespoons of the chili-soaking liquid now and then, if needed, to ease the grinding.
11. The paste can be stored in an airtight container in the refrigerator for 1 month, or in the freezer for up to 3 months (freeze in ice cube trays for easy portioning later).