Combine the cranberries and figs with the orange juice and leave to marinate until needed.
Cook the chestnuts on a simmer for about 25 minutes. While the chestnuts are cooking, prepare other ingredients - Note 1.
Wash the kale and remove the stem. Drain any excess water. Cut each leaf in half and cut into ribbons.
Clean and butterfly the tenderloin. Flatten the meat out with a meat tenderizer - Note 2 & 3.
Place the plastic wrap onto your cutting board or workspace. Add the pancetta on top, followed by the pork tenderloin. Season the meat with salt, freshly ground pepper, and fennel seeds. Set aside.
PREPARE THE FILLING
Clean the chestnuts by peeling the skin off and coarsely chop them - Note 1.
Sauté garlic, ginger, and red pepper flakes with 2 tablespoons of olive oil over low heat to release the flavors. Turn the heat to medium, add the kale and drain the orange juice marinade into the pan, reserving the dried fruit.Cook the kale for 5 to 8 minutes or until the juice has a creamy consistency.
Add the apricot jam, parsley, dried fruits, walnuts, chestnuts, and Brie cheese. Mix to incorporate all the ingredients.
ASSEMBLE
Add the prepared filling and place it in the middle of the pork tenderloin.
Wrap the meat tightly along the short edge, making sure that the bacon wraps the meat all the way. Place it seam-side down on a baking sheet. Brush the top with 1 tablespoon of olive oil.
Bake for 15 minutes, lower the temperature to 200ª/400ºF and bake for another 10 minutes.
NOTES
If you are using precooked chestnuts skip this step.
To clean the pork tenderloin you need to remove the silver skin.
First, slip a sharp knife under the silver skin and cut by pushing the knife away from you to remove the silver skin.
Now take the cut piece into your hand and run the knife away from you, under the still detached silver skin.
While cutting, push the knife slightly upwards, as if sliding along underneath the silver skin.
Repeat the process if there is any silver skin left on the tenderloin.
To butterfly the pork tenderloin:
Cut along the long edge leaving about 1/2in of meat uncut.
Now repeat on each side to further "open" up the tenderloin.