How to Make It
Heat oven to 450° F. On a rimmed baking sheet, toss the beets with 3 tablespoons of the oil, ½ teaspoon salt, and ¼ teaspoon pepper. Roast until beginning to soften, 13 to 15 minutes. Add the oranges to the baking sheet and roast, tossing once, until the beets and oranges are tender, 15 to 17 minutes more. Add the arugula and toss to combine.
Meanwhile, heat the remaining tablespoon of oil in a large skillet over medium heat. Season the pork with the oregano, thyme, and ½ teaspoon each salt and pepper and cook until browned and cooked through, 7 to 9 minutes per side. Serve with the beets and oranges.