Line pie plate with pie dough. Put in the refrigerator for 20-30 minutes (about the amount of time to prepare the filling) to prevent the dough from shrinking while cooking. Preheat oven to 375°F. If you are using frozen vegetables remove from the freezer while you are working on the rest of the filling.
In a large sauce pan, melt butter on medium high heat. Add onions, garlic, shallots, salt, and pepper, and cook about 4-5 minutes, until onions just start to soften. Add flour and stir constantly for 2 minutes. This will remove any "floury" taste from the filling.
While stirring, slowly add chicken stock to flour mixture. Add bay leaf, crushed red pepper, rosemary, thyme, and potatoes. Let simmer for 8-10 minutes. Add your vegetables and protein and let simmer for an additional 4 minutes.
Remove pan from heat and add half and half, celery seed, and Tabasco. Mix well, then remove the bay leaves, and set aside.
Make egg wash by combining egg and 1 tbsp half and half. Lightly brush bottom of the pie crust with egg wash. The proteins in the egg create a barrier so that the crust will not get soggy while cooking! Ladle in filling, then put top crust on. Crimp edges together well so prevent any filling from leaking out. Brush top crust with egg wash and sprinkle with thyme, salt, and pepper. Cut 5-6 small slits in the top to allow steam to vent out.
Cook for 45-50 minutes, until crust is golden brown. Enjoy!