1 Make the pie crust dough. Pulse the flour and salt together in a food processor. Add the chilled butter cubes to the food processor and pulse 5 times. The dough should resemble a coarse cornmeal, with some pea-sized pieces of butter. Slowly add the chilled water (make sure there are no small ice cube bits), just a tablespoon at a time, pulsing once after each addition, until the dough just sticks together when you press some between your fingers. Empty the food processor, placing the dough mixture on a clean surface. Use the heel of your palm to shmoosh the dough mixture onto the table surface a few times. This action will help flatten and spread the butter between layers of flour, so that the resulting dough will be flaky. Once you’ve done this a few (5 or 6) times, use your hands to mold the dough into a disk. Sprinkle the disk with a little flour, wrap it in plastic wrap, and let it chill for an hour, or up to 2 days, before rolling out.
2 To make the filling, heat the oil over medium-high heat and sauté the onion, celery, green pepper and jalapeno, stirring often, until they are soft, about 6-8 minutes. Add the garlic, turkey meat, Cajun seasoning, and salt. Mix well and cook another 1 minute, stirring once or twice.
3 Bring the stock and beer to a boil in a small pot. Sprinkle the flour over the turkey and veggies and mix well. Cook for 4-5 minutes, stirring often and making sure no flour burns on the bottom of the pan. Slowly pour in the hot stock-beer mixture, stirring. It will seize up at first, then, as you pour in more stock and stir, will form a silky sauce for the turkey. Add the tomatoes and cook until the mixture thickens, about 3-5 minutes. Pour the filling into a 2-quart casserole or, if you wish, into individual ramekins.
4 Prepare the crust. Roll dough out on a lightly floured surface to a little less than a quarter-inch thick. If you are using a casserole, roll into a sheet a little larger than the dish. If you are using ramekins (use 10 ounce ramekins), cut the dough into 6 rounds that are slightly larger than the circumference of the ramekins. Lay the dough onto the filling. Fold the excess dough under itself and use the tines of a fork to press the dough against the edge of the ramekins. Cut a 1-inch vent into each individual pie, or several if you are making a casserole. Whisk together in a small bowl the egg yolk and cream for an egg wash. Use a pastry brush to paint the egg wash over the crust. This will help the crust brown nicely.
5 Bake at 400°F for 25 minutes, or until the pastry is golden and the filling is bubbling. Let cool for at least 5 minutes before serving.