In a pot large enough to hold at least 20 cups of water, add pig tails. Cook on medium heat to render fat. Pat salt beef dry with a towel. When drippings have accumulated, add salt beef to pot and saute until brown.
Once browned, add 6 1/2 pints of water and bring to a simmer. Simmer for 1 hour, occasionally skimming off the foam that rises to the surface and clings to the sides of the pot.
After 1 hour, add the yams and coco. Add ice water to congeal fat and cause it to rise to the top. Skim off fat. Simmer for 1/2 hour more.
Add okra and kale. Add thyme, salt, and pepper to taste. Add chopped onion and scallion. Cook another 1/2 hour. Add callaloo or spinach and boil for 3 minutes. Serve immediately.
Recipe courtesy of Graham Kerr