Sprinkle salt evenly on chicken breasts. Cover and refrigerate overnight
(Optional) On day of cooking, remove chicken breasts 30 minutes before cooking to warm up a bit. This is ideal but not a deal breaker if you're not able to
Put chicken breasts on a heat proof shallow dish. Sprinkle white pepper, coat with sesame oil and grapeseed oil evenly
Place chicken breasts in steamer and steam for 15 minutes (please see steamer hack in post above)
Check internal temperature is 165 F and remove from steamer. Pour out any liquid accumulated on plate. Let rest for 5 minutes
Salting 24 hours before steaming will produce more flavourful and tender chicken breasts. However, if you're short on time, adding the salt with the seasonings right before cooking won't be a deal breaker. The ginger scallion sauce will more than make up for it!
If you don't have a steamer, you can use a deep pot with a trivet placed at the bottom. Add water till the level hits right below the trivet. Add the chicken on top of the trivet. Cover the pot and bring to a boil. Once boiling, lower the heat to medium. Make sure the pot doesn't boil dry without water before cooking is finished