2. Combine vinegar, olive oil, honey, salt, and pepper in a small bowl, stirring with a whisk. Drizzle vinegar mixture over peach mixture; toss well to coat. Sprinkle with cheese and basil.
Meanwhile, heat the remaining tablespoon of oil in an ovenproof skillet over high heat. Season the fillets with salt and pepper and add them to the pan, flesh side down. Cook them until browned on one side, 3 to 4 minutes. Then flip them, brush on half the honey mustard, and place the pan in the oven. Bake until the salmon is firm and flakes easily (but before white solids begin to form on the surface), about 5 minutes. Remove the fillets from the oven and brush them with more honey mustard. Serve the salmon with the asparagus.