In a large saucepan melt 1/3 cup butter.
Add mushrooms, saute 2 minutes.
Sprinkle with 1/4 cup flour and continue cooking for about 5 minutes, stirring constantly, do not brown.
Add chicken stock and 2 cups of milk. Stir to combine and bring just to a boil.
Reduce heat and add thyme, Tabasco sauce, salt and pepper.
Mixture should thicken, simmer for 10 minutes.
Add diced turkey and mixed vegetables, stirring to combine.
Spoon into greases 12 cup casserole.
Top with dumpling crust.
DUMPLING CRUST.
In a bowl, blend remaining ingredients except milk and butter.
Cut butter in with pastry blender to form a coarse crumb.
Add milk, stirring just to combine.
Turn dough onto floured surface and knead a few times.
Roll out to fit top of casserole.
Place directly on top of turkey mixture and cut steam vents.
Bake at 400 F for 25 to 30 minutes.
To save time I often use frozen mixed vegetables instead of the peas and carrots.