Bring broth to a boil in a large saucepan; stir in grits. Reduce heat, and simmer, stir in grits. Reduce heat, and simmer, stirring occasionally, 5 to 7 minutes or until thickened. Stir in butter and next 3 ingredients.
Combine cornmeal and next 4 ingredients; stir into grits mixture. Pour into a slightly greased 11- x 7-inch baking dish.
Bake at 425° for 45 minutes or until lightly browned. Cut into triangles, and serve with Savory Mushroom Sauce; garnish, if desired.