Melt butter and chocolate over low heat, stirring until blended.

Remove from heat and gradually blend in evaporated milk.

In a large bowl, mix sugar, cornstarch, and salt.

Add eggs and vanilla and beat well.

Gradually blend the chocolate mixture into the egg mixture.

Pour the mixture into an unbaked 9-inch deep dish pie crust.

Combine pecans and coconut in a bowl.

Sprinkle the pecan-coconut mixture over the pie filling.

Bake at 375°F (190°C) for 45 to 50 minutes, or until the filling is puffed and browned.

If the top browns too quickly, cover loosely with foil during the last 15 minutes of baking.

Cool the pie for at least four hours before cutting and serving. The filling will set as it cools.