Heat the soy sauce, vinegar, sugar, and ginger in a large nonstick skillet over medium heat until the sugar melts, about 3 minutes. Season the meat or fish with the salt and pepper and add to the skillet. Braise the meat or fish (3 minutes each side), then add the onion, pear, wine, and orange zest and juice. Cover, reduce heat to low, and cook 20 minutes for the chicken, 15 minutes for the pork, or 5 minutes for the salmon. Transfer the meat or fish to 4 plates (slice the pork). Simmer the sauce to thicken, and season with salt and pepper. Top the meat or fish with the pear, onion, and sauce.