Put the callaloo, kale, and beef in stockpot, cover with the water, and bring to a boil. Reduce to a simmer and cook until the beef is tender, about 1 hour.
To the callaloo mixture, add the coconut milk, sweet potatoes, potatoes, scallions, thyme, Scotch bonnet, and freshly ground pepper. Bring back to a simmer for 1/2 hour more. Season at the end with the salt, to taste.