Preheat your oven to 375°F (190°C) and prepare a baking dish by lightly oiling it or lining with parchment paper.

In a skillet, heat olive oil over medium heat; sauté the onion until translucent, about 3-4 minutes. Stir in garlic and sage, cooking for another minute.

In a mixing bowl, combine the sautéed mixture with cranberries and breadcrumbs. Add chicken broth gradually; season with salt and pepper.

Butterfly the pork tenderloin by slicing it lengthwise without cutting all the way through, then pound to an even thickness.

Fill the pork with stuffing and roll it tightly, securing with kitchen twine every 1-2 inches.

Optionally sear the tenderloin in the skillet for 1-2 minutes on each side until golden brown.

Transfer to the baking dish, optionally brush with glaze, and roast for 35-40 minutes until the internal temperature reaches 145°F (63°C).

Remove from oven, tent with foil, and let rest for about 10 minutes before slicing.