To make the sauce, combine the light soy sauce, dark soy sauce, sesame oil, rice vinegar, honey, grated ginger and garlic in a bowl.
Pre-heat the oven to 200 degrees Celsius (390 Fahrenheit).
Add the vegetable oil to a pan , arrange the salmon fillets skin down, and fry for 2-3 minutes until the skin crisps up, then turn over, and fry for another 2-3 minutes (can be done in 2 batches or at once if you have a large pan).
Arrange the salmon fillets on a baking tray that has been lined with kitchen foil, then drizzle half of the sauce over.
Bake for about 15 minutes or until cooked though.
Combine the cornflour with 1 tablespoon of cold water, mix well, then add it to the teriyaki sauce.
Add the sauce and cornflour mixture to a pan set over a medium heat, and whisk for 1-2 minutes until the sauce thickens slightly.
Once the salmon fillets are baked, coat them with the thickened teriyaki sauce, and serve with sesame seeds if you wish, and with the broccoli on a bed of rice.