Drain and rinse the soaked black-eyed peas. Place them in a blender or food processor.
Add the chopped onions, red and green bell peppers, vegetable oil, ground crayfish (if using), ground paprika, ground cumin, dried thyme, salt, and freshly ground black pepper to the blender or food processor.
Blend the mixture until it forms a smooth batter. Add vegetable broth or water as needed to achieve a thick but pourable consistency.
Pour the batter into a mixing bowl and whisk or stir vigorously to incorporate air into the mixture. This step helps to achieve a fluffy texture.
Add any optional chopped vegetables, cooked beans, or vegan protein to the batter if desired. Stir well to combine.
Prepare your steaming pot or steamer by filling it with water and placing a steaming rack inside. If using aluminum foil or moi moi leaves for wrapping, cut them into square or rectangular shapes and lightly oil them.
Pour the batter into individual aluminum foil/moi moi leaves or into a greased baking dish.
Place the wrapped or covered batter onto the steaming rack in the pot or steamer. Cover the pot with a lid.
Steam the Moi Moi for about 45 minutes to 1 hour, or until it is firm and fully cooked.
Remove the Moi Moi from the steamer and let it cool for a few minutes before unwrapping or serving.
Serve the Nigerian Moi Moi warm or at room temperature as a main dish or as a side dish with rice, plantains, or other Nigerian accompaniments.