1. Preheat oven to 350 degrees F. Sprinkle nuts on bottom of pie shell and set aside.
2. Combine chocolate and butter in top of a double boiler over gently simmering water. Whisk until melted and well blended. Remove from heat and whisk in sugar.
3. Beat small amount of warmed chocolate into eggs. Add to chocolate mixture and blend well.
4. Pour into pie shell (uncooked mixture will not fill shell) and bake until filling is puffed, about 25 minutes. Serve warm or at room temperature with whipped cream or ice cream.