Preheat oven to 325 degrees F.
For the crust: In a large bowl, blend together the butter and cream cheese. Stir in flour and chill for 1 hour in the refrigerator. Separate dough; reserving 1/3 for pie tops, and using 2/3 for pie crust bottoms. To form bottom portions of dough, create dough balls approximately 1-inch in diameter and place into bottom of muffin tin cups, flattening to form crust bottoms. Bake crusts only until golden brown, about 20 minutes.
For the filling: In a saucepan, add butter and flour, stirring together over heat to create a roux. Cook until mixture is the color of peanut butter. Add all vegetables and saute until soft, about 5 to 10 minutes. Add crawfish, Cajun seasoning, and salt and pepper to taste. Saute mixture for 2 to 3 minutes. Add chicken stock and cook, stirring, until mixture boils and thickens. Spoon mixture into crusts. Top with circles of unbaked dough cut from the reserved 1/3 of original dough. Make a small slit in the top of the dough to allow steam to escape. Bake for 20 to 25 minutes or until golden brown. Serve while warm.