Steps
1. Preheat your oven to 200°C (400°F).
2. Rub the pork tenderloin with olive oil, then season with thyme, rosemary, garlic powder, salt, and pepper.
3. Heat a skillet over medium-high heat and sear the pork on all sides until golden brown (about 3-4 minutes).
4. Transfer the pork to a baking dish and roast in the oven for 15-20 minutes, or until the internal temperature reaches 145°F (63°C).
5. While the pork is roasting, peel and chop the potato into cubes. Boil in salted water until tender (about 10-15 minutes).
6. In the last 5 minutes of cooking, add the green beans to the boiling potatoes.
7. Drain the potatoes and green beans, then add butter and mash the potatoes until smooth. Season with salt and pepper.
8. Let the pork rest for 5 minutes before slicing.
9. Serve the sliced pork with the mashed potatoes and green beans on the side.