To a large pot add the sliced beef, smoked fish, half the diced onion, and 1 cup of water. Simmer for 25 minutes. Add another 2 cups of water and let it cook. In a frying pan, heat the palm oil and add the remaining onion. Fry for 3-4 minutes, then add the tomato puree and pepper. Stir until thickened, then add to the beef stock, add grounded melon seeds and allow to cook for another 20 minutes. Add the crayfish, spinach, and seasonings to taste, cook for another 5 minutes, then remove from heat.