1 pound Brussels sprouts, trimmed and halved (or quartered if large)
1 small red onion, halved and sliced 1/2 inch thick
2 tablespoons vegetable oil
Kosher salt and freshly ground pepper
1 tablespoon apple cider vinegar
4 teaspoons honey
1 teaspoon Sriracha
4 boneless center-cut pork chops (3/4 inch thick; about 1 1/4 pounds)
2 tablespoons dijon mustard
6 tablespoons panko breadcrumbs
2 tablespoons finely chopped fresh parsley
Put a baking sheet on the middle oven rack and preheat to 450 degrees F. Toss the Brussels sprouts and red onion in a large bowl with 1 tablespoon vegetable oil, 1/2 teaspoon salt and a few grinds of pepper. Spread on the hot baking sheet in a single layer and roast, without stirring, until tender and charred in spots, 20 to 25 minutes.
Meanwhile, whisk the vinegar, honey, Sriracha and a pinch of salt in a large bowl. Set aside.
Season the pork chops with salt and pepper and brush the mustard on both sides. Toss the panko with 1 tablespoon parsley, a pinch of salt and a few grinds of pepper on a plate. Press both sides of the pork chops in the mixture to evenly coat. Heat the remaining 1 tablespoon vegetable oil in a large nonstick skillet over medium-high heat. Add the pork chops and cook until browned and cooked through, 4 to 5 minutes per side. (Reduce the heat to medium if the crust gets too dark.)
Add the roasted vegetables to the honey-Sriracha sauce and toss to coat. Serve with the pork chops. Sprinkle with the remaining 1 tablespoon parsley.