Cut the meat into bite-size chunks. Boil it with 1/2 teaspoon of the salt and half the onions in a cup of water for about 10 minutes. Meanwhile, in a large, heavy pot, warm the palm oil over low heat for about 7 minutes. While it heats, grind or crush seperately the egusi seeds, peppers and crayfish, and tear the greens into small pieces.
Remove oil from the heat and quickly stir in the remaining onions and tomato paste. With a slotted spoon, remove meat from its pot and pour the cooking water into a measuring cup. Add enough water to make 1 cup and after the water has cooled enough not to spatter you--pour the water carefully into the pot. Return to medium heat. One after the other, 2-3 minutes apart, add the egusi, greens, pepper, okra, crayfish and remaining salt. Cook another 8-10 minutes after all the ingredients have been added, or until the meat is done to your liking.
Variation: If you can't get ugusi seed, substitute 1/4 cup of either tapioca flour or quick-cooking tapioca. Before adding it to the soup pot, whisk it into a smooth paste by mixing it with a bit of the hot broth.