Plug in the crock pot/slow cooker and turn setting to High. Blend all Spice Paste ingredients in a food processor until fine. Scoop out, and set aside. Season lamb cubes with a little salt and put aside.
In a wok, heat up oil, stir-fry turmeric leaf and kaffir lime leaves until fragrant.
Turn heat to slightly medium-high, add blended Spice Paste, stir-fry until fragrant, or until color changes for 5 minutes.
Put in lamb cubes, stir well and continue cooking for 5 minutes.
Pour in coconut milk and toasted coconut and bring to a quick boil. Turn off heat and move all pre-cooked contents from wok into crock pot and braise for 1 1/2 hours.
Remove pot cover, stir and check to make sure the dish is not too dry and the lamb is tender enough to your liking, about 1 - 1 1/2 hours, or until the meat is tender enough. Turn off heat. Unplug crock pot and allow the dish to sit for 30 minutes to 1 hour. The sauce will slowly evaporate, and may appear slightly dry and thickened. The Lamb Rendang is ready to dish out and serve with steamed white rice or coconut rice.