Add the soy sauces, rice wine, honey and vinegar to a small 15cm or 6" saucepan. Bring to a boil and cook for 60 seconds, stirring continuously.
Pour into a shallow bowl. Run a little cold water in a sink and add the bowl to cool the sauce as quickly as possible. If you are not in a rush, you can let this happen naturally.
Place the salmon fillets flesh side down in the sauce.
Heat a dry 30cm or 12" frying pan or skillet over a high heat and toast the Szechuan pepper for 60 seconds. Then remove and crush in a pestle and mortar or spice grinder
Return the pan to the heat and toast the sesame seeds for 60 seconds, and set aside.
Return the pan to the heat and add the salmon fillets skin side down. Cook for 4-5 minutes.
Whilst the fish is cooking sprinkle the flesh side with the Szechuan pepper.
Just before you flip the fish, pour in the rest of the marinade; it will bubble rapidly.
Flip the fish and remove from the heat. Allow to sit for 60 seconds before serving.
I like to remove the skin and brush the flesh underneath with the marinade which should be sticky.