Yet ANOTHER Christmas recipe!! (I'm noding them as I bake.)
Put the milk and sugar in a large saucepan. Heat to boiling. Cook for five minutes, stirring all the time. Remove from heat, and add marshmellows, nuts, chocolate, and vanilla. Stir with a wooden spoon until melted. Pour into a buttered 9" pan. Let cool, then cut.
PLEASE NOTE: I'm not guaranteeing anyone but my grandmother can actually make this in five minutes.
Update: I just made it. So, here's a handy tip: If you think you won't be able to tell when everything's melted, leave the nuts out until you're sure. They make little lumps which look like unmelted chocolate chips.