Combine the onions, bell peppers, celery, crawfish, and bread in a bowl and toss thoroughly. Finely chop this mixture in a food processor by pulsing the motor on and off several times. Do not puree. Transfer the mixture to a bowl and add the egg,, green onions, parsley, salt, cayenne, and black pepper. Mix well and shape into balls the size of walnuts.
Season the bread crumbs with the rub. Roll the balls in the bread crumbs. Heat the oil to 360?F. and deep fry the boulettes until golden brown. Or bake them in a preheated 350?F. oven for 15 to 20 minutes, or until golden brown.
Serve hot, warm, or at room temperature.
Yield: about 2 1/2 dozen