Soak the black-eyed peas in water for 10 to 15 minutes. This will help to soften the beans, making them easier to cook and peel.
After soaking, drain the water, and gently rub the beans between your palms to peel off the skins. Rinse the beans in cold water to remove the skins, repeating this process until most of the skins have been removed.
In a large pot, combine the peeled beans, diced onions, and water. Cook the beans over medium heat for 1 hour or until they become tender. Make sure to keep an eye on the water level and add more if needed to prevent the beans from burning.
Once the beans are cooked, blend them with a hand blender or immersion blender until you achieve a smooth, creamy texture. You can also blend the beans in a high-speed blender.
Return the puree to the pot, the crayfish powder, ground locust beans (if using), stock cube, and salt to taste. Stir well to combine all the ingredients.
Simmer the gbegiri soup over low heat for 3 to 5 minutes or until thickened to your desired preference, stirring occasionally to prevent the soup from sticking to the bottom of the pot.
Taste the soup and adjust the seasoning with more salt or stock cubes if necessary. If the soup is too thick, you can add some chicken or vegetable broth to achieve your desired consistency.
Serve the gbegiri soup hot. It can be eaten alone or accompanied by tuwo rice, amala and ewedu.