Sear the tenderloins in butter, over high heat. Reduce heat and finish cooking (about 5 minutes). Remove meat.
Deglaze pan with cider, over high heat, to dissolve concentrated juices.
Add maple syrup or organic syrup and boil down by one half.
Add thickened brown stock, boil down slightly, and check seasoning.
Finish sauce by adding pieces of cold butter, whisking until sauce is smooth. Remove immediately from heat and reheat tenderloins in the sauce off the stove. Serve at once.
