Heat oven to 350° F. Slice the pork into 8 thin cutlets. Heat the oil in a large ovenproof skillet over medium-high heat. Season the pork with 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper. Cook the pork until it's browned, about 2 minutes per side. Spoon the tomato sauce over the pork. In a small bowl, combine the bread crumbs, sage, lemon zest, garlic, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper; sprinkle evenly over the sauce. Roast until bubbling and browned, 10 minutes. Meanwhile, fill a large pot with cold water. Add the remaining salt and bring to a boil. Add the green beans and cook until tender, about 5 minutes. Drain them and plunge them into cold water to chill. Drain again and toss with the arugula. Serve with the pork.
Tip: To add flavor to the green beans and arugula, toss them with butter and a squeeze of lemon. For 1/2 pound of green beans, use 2 tablespoons of melted unsalted butter and 1 tablespoon of fresh lemon juice.