*Note: Assam skin is the skin of the tamarind fruit, and can be purchased online.
**Note: Gula jawa is Indonesian palm sugar. You can also purchase it online. To make the syrup, place the sugar in a small saucepan and set it over low heat. Cook, without stirring, until the sugar melts into syrup. Keep an eye on it to make sure the sugar does not burn.
Combine the first 6 ingredients in the bowl of a food processor and purée. Season the beef with 1 ½ quarts of the paste and transfer to several large bowls. Cover with plastic wrap, place in the refrigerator, and marinate for 48 hours. Reserve 1 pint of marinade to make the dang sauce.
Preheat the oven to 225 degrees.
Remove the beef from the refrigerator. To braise, portion the short ribs into 4 large Dutch ovens. Season each pot with the kosher salt and add the assam skin, coconut milk, and chicken stock. Put a piece of parchment paper in each pot, seal with aluminum foil, and cover each pot with a lid. Braise until tender, approximately 6 hours.
After braising, add the toasted coconut to each pan, and let cool to room temperature. Transfer to the refrigerator. Once cooled, strain the braising liquid through a colander and separate the short ribs into 10-ounce portions. Reserve the braising liquid for the dang sauce.
Add the reserved beef marinade, shallots, garlic, and palm sugar to the bowl of a food processor and blend. Heat the oil in a saucepot over low heat, and sweat the paste. Add the coconut milk and 8 ½ ounces of reserved braising liquid and simmer on low to reduce. Season with salt, to taste, and blend with a handheld mixer.
Spoon the sauce onto a platter. Add as many ribs as you would like to serve for this occasion over the sauce and season with lime and sea salt. Drizzle gula jawa syrup over the meat, and sprinkle the toasted coconut and the kaffir lime leaves on top. Serve the ribs with a side of pickled vegetables and a large bowl of steamed coconut rice.