HEAT oven to 375°F.
MELT chocolate and butter in medium saucepan on very low heat, stirring constantly. Remove from heat; gradually stir in milk until well blended.
MIX sugar, cornstarch and salt in medium bowl; whisk in eggs and vanilla. Gradually whisk in chocolate mixture. Pour into crust; sprinkle with coconut and nuts. (Filling will almost completely fill crust.)
BAKE 45 min.or until top is puffed and browned, covering pie loosely with foil after 30 min. (Filling will be soft, but will set while cooling.) Cool 15 min. Refrigerate 4 hours.