Preheat oven to 375 degrees.
In large mixing bowl, pour milk over bread slice and mash.
Add remaining ingredients and mix very well.
Place in large pan, double lined with foil.
Spread glaze on top of loaf.
Bake for 60 minutes or until desired browness.
Place 1/8 cup pan drippings and 1 T. margarine into a saucepan over medium heat.
Whisk in 2 T. gluten free flour and cook for 1 minute, stirring constantly.
Gradually whisk in beef broth, stirring constantly.
Remove from heat and whisk in milk and spices.
Return pan to heat and simmer until thickened.
You may add 1 T. corn starch mixed with 1 T. cold water if you like thicker gravy.
Add sliced mushrooms, if desired (canned or sauteed).
Serve with mashed potatoes.