1. Place the orange zest, juice, wine, orange juice concentrate, lime (if using),and blacken in a fry pan Mix well, then turn the heat to high and reduce by 1/2.
2. Strain, then place back in the pan and add the cream. Cook long enough to reduce by half again.
At this point you can set the sauce aside to finish later.
3. Re heat, if you've prepared it early, turn the heat off and add the butter. Stir until blended, rich, and shiny.