Heat oven to 400 F. In a food processor, pulse the bread and 2 tablespoons of the oil to form coarse crumbs. Spread on a rimmed baking sheet and bake until crisp, 5 to 6 minutes.
2
Toss with the scallions, 1⁄2 teaspoon salt, and 1⁄8 teaspoon pepper.
3
Meanwhile, heat 1 tablespoon of the remaining oil in a large ovenproof skillet over medium-high heat. Season the pork with 1⁄2 teaspoon each salt and pepper and cook until browned, 2 to 3 minutes per side. Transfer the skillet to the oven and roast the pork until cooked through, 6 to 8 minutes.
4
In a large bowl, toss the spinach and beans with the vinegar, oregano, the remaining tablespoon of oil, 1⁄2 teaspoon salt, and 1⁄8 teaspoon pepper. Top the pork with the bread crumbs mixture. Serve with the salad.