Preheat oven to 350°F.
Rollout pie crust and ease into pie pan. Trim edges, creating decorative cutouts with trimmings if desired. Add decorative crimping or press with a fork to edge. Chill crust and decorative pieces in the freezer 10 minutes.
Spread melted chocolate over bottom of crust, then chill an additional 10 minutes or until chocolate is firm.
While crust is chilling, whisk the filling ingredients in medium bowl to blend.
Add pecans to chilled crust (as many as can fit), then pour filling over all. Add the decorative crust pieces if desired. Brush edges and decorative pieces with egg wash.
Bake until filling is set and slightly puffed, about 1 hour, checking after 45-50 minutes to avoid over-browning the pecans. If edges are browning too quickly, cover with foil or a pie shield after 30 minutes.
Transfer pie to rack and cool completely. Don’t worry if the filling has cracked a bit as it puffs up…it will subside when cooled.