Press one pie crust into an un-greased pie plate. Bake the pie crust (use pie weights) at 400 degrees for 7 minutes. Set aside to cool.
Heat the oil and flour over medium heat, stirring regularly until it turns a caramel color. It should take about 10-15 minutes.
Add the onions and green peppers and cook for about 1-2 minutes.
Add the tomatoes and Cajun seasoning and cook for 1-2 minutes.
Add the fish broth and bring to a boil; simmer for 5 minutes.
Add the cream and crawfish and bring back to a simmer for 5 minutes. Add additional Cajun seasoning to taste if desired.
Remove from heat and pour into the par-baked pie crust.
Top with the second pie crust. Cut slits in top of crust so the filling doesn't leak out. Make sure to seal the pie crust around the edges to prevent the filling from leaking out.
Brush with the egg wash (1 beaten egg mixed with 1 tbsp. water).
Bake for 25-30 minutes, or until the crust is golden brown.
Remove from oven and let cool for 20 minutes. Slice and serve garnished with green onions and Louisiana hot sauce.