Combine the flour and salt in a mixing bowl. Add the shortening and work it in with your hands until the mixture resembles coarse meal. Using the tines of a fork, stir as much of the water as you need to bring the dough together, 1 tablespoon at a time. Work it with your hands until you have a smooth ball of dough. Don’t overhandle the dough. Wrap it in a plastic wrap and refrigerate for at least 1 hour.
Combine the onions, bell peppers, and celery in a bowl and season with the salt, cayenne, and paprika.
Melt the butter in a skillet over medium-high heat. When the foam subsides, add the seasoned vegetables and sauté until soft and brown, 6 to 7 minutes. Add the crawfish tails and cook for 5 to 6 minutes, stirring occasionally. Dissolve the flour in the water and add to the crawfish mixture. Stir for 1 to 2 minutes, or until the mixture thickens. Remove from the heat and add the parsley and green onions. Cool to room temperature.
Preheat the oven to 375ºF. and lightly oil a baking sheet.
Remove the dough from the refrigerator and place it on a lightly floured surface. With a knife, cut the dough into 8 equal portions. Lightly flour each piece. Using your fingers, flatten each piece into a 6-inch round, about 1/4 inch thick. Fill the center of each one with a heaping 1/3 cup of the crawfish mixture. Brush the edges of each round some of the beaten egg. Fold the rounds in half and crimp the edges with the tines of a fork. Brush the tops of the turnovers with the remaining beaten egg.
Place the turnovers on the baking sheet about 1 inch apart. Bake for 45 minutes, or until golden brown.
Yield: 8 turnovers