Pat the pork tenderloin dry with paper towels and season with a pinch of salt and black pepper on all sides.
Heat a non-stick skillet over medium-high heat and add the olive oil.
Sear the pork tenderloin for about 2-3 minutes per side until a golden crust forms.
Lower the heat to medium and continue cooking, turning occasionally, for about 10-12 minutes total or until the pork reaches an internal temperature of 145°F.
While the pork cooks, core and slice the apple into thin wedges.
In a separate small pan, melt the unsalted butter over medium heat. Add the apple slices and a pinch of salt to help draw out the juices and allow them to caramelize for about 4-5 minutes, stirring occasionally.
Preheat your oven to 425°F. Toss the green beans with a light drizzle of olive oil, salt, and pepper, then spread them in a single layer on a baking sheet.
Roast the green beans in the oven for about 10 minutes until they are tender-crisp.
Once everything is cooked, slice the pork tenderloin, plate it alongside the caramelized apples and roasted green beans, and serve immediately.