Tear the chilis into pieces and place in the bowl of a food processor. Add the lemongrass, garlic, ginger, and salt to the bowl. Run on high until all the ingredients are in small pieces, scraping down the sides as needed. Add the cardamom, coriander, cumin, and shallots to the bowl and process until smooth. Mix in the shrimp paste. Set aside until ready to use. Makes 10 tablespoons.