In a small saucepan, melt the chocolate and butter over low heat, stirring to mix well. Remove from heat and blend in evaporated milk. Set aside.
In large bowl, combine the sugar, cornstarch, and salt. Stir in eggs and vanilla until well blended. Gradually stir in chocolate mixture. Pour into pie crust.
Combine the pecans and coconut and sprinkle over the top. Bake at 375 for 45-50 minutes, until puffed and browned*. Cool for at least thirty minutes (or longer) before serving. Refrigerate any leftovers and serve reheated or cold.
*Check pie after 30 minutes of baking and if coconut is very brown, cover with foil for remaining cook time to prevent burning.