Preheat oven to 425°F.
Line pie pan with pastry and refrigerate until ready.
Melt butter, and saute onions until golden.
Blend in flour, salt, pepper and thyme. Cook over low heat for 1 minute. Remove from heat.
Stir in chicken broth and non-dairy creamer. Heat to boiling and boil 1 minute, stirring constantly. Stir in chicken and vegetables. Allow to cool 10 minutes.
Pour into pastry-lined pan. Cover with pastry top, and seal edges.
Bake 35-40 minutes or until golden brown.