1. Preheat oven to 400°F and line a 9x13-inch roasting pan with foil.
2. Use a sharp knife to make small insertions in the top and sides of the pork tenderloin – make the insertions about 1 inch deep.
3. Press the peeled garlic cloves into the insertions.
4. Combine the rosemary, salt and pepper in a small bowl then rub the mixture into the pork tenderloin.  
5. Place the tenderloin in the prepared roasting pan, fat-side down, and roast for 30 minutes.  
6. Turn the tenderloin over and roast for 25 to 30 minutes longer or until a meat thermometer reads 155°F in the center of the pork.
7. Remove the roasting pan from the oven and let the pork stand for about 10 minutes.
8. To make gravy, pour off the juices from the pan into a small saucepan and keep warm over low heat.  
9. Whisk together 2 tablespoons coconut flour with about ¼ cup water and stir into the juices in the saucepan. 
10. Cook over medium-low heat, whisking until well incorporated. Let sit to thicken.  
11. Slice the pork tenderloin to the desired thickness and serve hot with the gravy.
12. Garnish with sprigs of fresh rosemary, if desired.

Notes