Preheat oven to 375º F.
Fry the bacon until crispy, adding the sage during the last 3 minutes of cooking. Remove to a paper lined plate to drain.
Create thin slices down the length of the pork tenderloin (approx 3/4 inch apart) without cutting all the way through. Tip - place two chopsticks on each side of the pork and allow them to be the stop for the knife as you slice down.
Push the cooked bacon and sage mixture down into each of the slits in the pork.
Slide the sliced sweet potatoes down into the slits with the bacon mixture.
Place the stuffed pork on a baking sheet and bake at 375º F for 30 minutes.
While the pork cooks, add the apricot marmalade, sherry and dijon mustard to a small saucepan and stir. Cook over medium heat for 3 minutes, or until bubbly. Remove from heat and set aside.
After the pork has cooked for 30 minutes, pour the glaze over the top and return to the oven to cook for an additional 5 minutes.
Remove from oven, slice and serve.