If using chicken and turkey thighs, coarsely grind the meat and skin through a 3/8-inch plate or chop coarsely in batches in a food processor.
In a large bowl, combine the ground poultry with the cilantro, fish sauce, basil, mint, garlic, ginger, curry paste, salt, red pepper flakes, black pepper, and cayenne. Knead thoroughly with your hands. Fry a small patty until done and taste for salt, pepper, and other seasonings.
Stuff the sausage into medium hog casings, and tie into 5-inch links.
The sausage will keep for 3 days in the refrigerator, or for 2 months in the freezer.
Recipe courtesy of Bruce Aidells' Complete Sausage Book (10 Speed Press, 2000)