4 center-cut pork loin chops (each about 8 ounces and 3/4 inch thick, frenched if desired)
1 cup freshly grated Parmesan cheese (about 4 ounces)
In a small bowl, mix the capers, their brine, olive oil, and parsley with a fork to combine. Season to taste with salt and pepper.
Coat the onions and zucchini with 2 tablespoons of the olive oil and season with salt andpepper. Grill the onions and zucchini for about 2 to 3 minutes per side, or until seared with grill marks and just tender. Remove from the grill and transfer to a cutting board.
Cut the zucchini diagonally in half. Very coarsely chop the onions. Toss the zucchini and onions with the cherry tomatoes in a 1 1/2- to 2-quart flameproof baking dish. Set aside at room temperature.
Pat the pork dry with paper towels. Coat with the remaining 1 tablespoon oil and season with salt and pepper. Grill the pork for about 3 minutes per side, or until seared golden brown and barely pink when pierced at the bone with the tip of a small sharp knife. Transfer to a platter and cover loosely with aluminum foil.
Sprinkle the Parmesan cheese generously over the vegetables. Broil, watching closely, for about 5 minutes, or until the Parmesan cheese has melted and is pale golden.
Divide the vegetables among four dinner plates and top each with a pork chop. Stir the vinaigrette, drizzle over the chops, and serve.