Pinch the pork loin all over with a fork and add it to a deep baking dish, not a very large one, you want it tightly together so the marinade gets all over it. You can also add the meat to a large ziplock back.
In a medium bowl, combine all the marinade ingredients and combine thoroughly.
Pour the marinade over the pork, cover with plastic wrap and marinate in the fridge for at least 1 hour or better overnight.
During the marinating time, make sure your flip the pork tenderloins onto the other side to ensure it marinates evenly.
Preheat the oven to 400F degrees.
Adjust the oven rack to the middle of the oven.
Once ready to roast, if you marinated the pork in the baking dish, just pop it into the oven.
If you marinated the pork in a Ziplock bag, add the marinade to a baking dish, add the pork, and bake.
The marinade in the baking dish should not cover the top of the pork, it should come to ½ or ⅔ of the pork.
Roast, uncovered, for 30-35 minutes or until a meat thermometer inserted in the thickest part of the pork reads 145F.
Once done, remove from oven, cover with foil and let it stand for 10 minutes before slicing. Please don't skip this step, if you slice it right away all the juice will come out.
If you want to make the glaze, add the marinade in which the pork was cooked to a medium pot over medium heat. Whisk in brown sugar and cornstarch and whisk until fully combined, with no lumps.
Simmer for 7-10 mins, until the mixture thickens, stirring occasionally.
Add the glaze to a small pitcher and drizzle it over the sliced pork before serving.
Preparation time does NOT include how long you marinate the pork.