Let the port tenderloin rest at room temperature for about 20 minutes before starting with the recipe.
Preheat the oven to 375°F (190°C).
Brush the tenderloin with a garlic clove (cut in half) or sprinkle with garlic powder if you like.
Sprinkle with salt, but don't overdo because the bacon will add to the salt later. And you can always add more salt later if needed.
In a large skillet add one tablespoon of olive oil and brown the pork on all sides, over medium heat, for about 5 to 10 minutes.
Finely chop the rosemary and the sage.
Lay out the bacon strips, slightly overlapping, on a cutting board or directly on your roasting pan.
Remove the tenderloin from the pan and place in the middle of the bacon. Sprinkle the tenderloin with the sage and rosemary on all sides.
Keeping the two pieces of tenderloin together, wrap the bacon around, overlapping a little.
Cut the potatoes in half or quarters if big. Toss in a bowl with one tablespoon of olive oil, salt and more rosemary.
Place the bacon wrapped tenderloin in the middle of a roasting pan, and add the potatoes to the sides.
Roast in the oven, at 375°F (190°C) until the internal temperature reaches a minimum of 145°F (65°C) to 160°F (70°C). It should take about 60 to 75 minutes, but it might vary based on the size of your meat.
Remove the pork roast form the oven, place on a cutting board or serving plate and cover with aluminum foil. Let it rest for 15 minutes, to allow the juices to redistribute.
Check the potatoes for readiness. Put them back in the oven if needed.
Saute' the spinach with one tablespoon of olive oil oil and one tablespoon of butter. Add thinly sliced garlic. Cook until wilted.
Slice the pork roast to desired thickness (I like it cut in thinner slices more than thicker, but it's a personal preference).
Serve with a spoonful of spinach, roasted potatoes and a drizzle of the cooking juice.