Pierce yams all over with a fork and place in a preheated oven at 425.
While the yams are baking, pour the vinegar, sugar and maple syrup into a saucepan, heat on high and stir until sugar dissolves.
Add fresh and dried cranberries, mix thoroughly and lower heat to a simmer and cover.
Allow sauce to reduce until the cranberries are visible above the sauce and set aside.
Butterfly turkey tenderloins (see Martha Stewart tutorial above).
Season butterflied tenderloins with salt, pepper and garlic.
Cut three pieces of twine for each tenderloin, ensuring each piece of twine is approx. 1 1/2 times the length of each tenderloin.
Place three pieces of twine under each tenderloin. Position one piece in the center of the tenderloin and then another piece either side of the piece of twine in the center of the tenderloin.
By now, the yams should be baked and soft, removed them from the oven and lower the oven to 325.
Once yams are cool enough to touch, cut them in half and then scoop out the insides into a bowl and discard the skins.
Add butter to yams and mix thoroughly, then add cranberry mixture.
Split yams and cranberry mixture in half and spoon onto the center of each turkey tenderloin.
Roll turkey tenderloin scooping up the sides into a tight roll.
Secure by tightly tying three strands of twine around each tenderloin, and cut excess twine.
Heat canola oil in skillet on high heat.
Once oil is hot, place turkey tenderloins into skillet and brown on all sides.
Once turkey tenderloins are browned, transfer to oven and cook for 45mins - 1 hour.