Steps
1. Preheat the oven to 400 degrees F.
2. Heat the olive oil in a roasting pan. Place the pork tenderloin in the pan and season generously with salt and pepper.
3. Roast the tenderloin for 30 minutes.
4. Meanwhile, in a medium bowl, combine the beer, mustard, garlic and a pinch of salt and pepper.
5. When the pork is done, take it out of the oven and brush it with the beer-mustard glaze.
6. Return it to the oven and bake for an additional 5-10 minutes, or until a thermometer reads 140 degrees F.
7. Let the pork rest for 10 minutes before slicing and serving.