Heat oven to 350° F. Heat the oil in a large ovenproof skillet over medium-high heat.
Season the pork with ½ teaspoon salt and ¼ teaspoon pepper. Cook until browned, about 2 minutes per side. Spoon the tomato sauce over the pork.
In a small bowl, combine the bread crumbs, sage, zest, garlic, ½ teaspoon salt, and ¼ teaspoon pepper. Sprinkle evenly over the sauce.
Roast the pork until it’s bubbling and browned, 10 minutes.
Meanwhile, fill a large pot with cold water. Add 2 teaspoons salt and bring to a boil. Add the green beans and cook until tender, about 5 minutes.
Drain the beans and plunge them into cold water to chill. Drain and toss with the arugula. Serve with the pork.