PREHEAT oven to 375°F. Melt chocolate and butter in saucepan on very low heat, stirring constantly. Remove from heat; gradually add milk, stirring until well blended.

MIX sugar, cornstarch and salt in medium bowl; beat in eggs and vanilla. Gradually add chocolate mixture, mixing until well blended. Pour into pie crust; sprinkle with coconut and nuts. (Crust will be quite full; filling will not rise over sides.)

BAKE 45 to 50 min. or until top is puffed and browned, covering loosely with foil for the last 15 min. to prevent overbrowning if necessary. (Filling will be soft, but will set while cooling.) Cool at room temperature 15 min., then refrigerate for at least 4 hours.