How do HK restaurants keep wok-fried scallops white, with no visible sear marks? After I add oil to pan on cook top and stir fry them, my scallops get brown sear marks. See photos:





But when ever I order Jade Scallops (西蘭花炒帶子  in Chinese) in HK restaurants, their scallops stay white! I phoned them all yesterday and they confirmed they wok fry them  – I don't think they're lying. Top to bottom – House of Canton in Kowloon Tong (first photo beneath),Ming Kee Restaurant in Wan Chai, 金龍冰室 in Tai Po  大埔, Joy Point Dim Sum in Tsim Sha Tsui.
Your scallops are (beautifully) seared on the outside because they are cooked all the way through in a very hot pan. The scallops in the Chinese stir fries stay pale because most of their cooking is done at low heat.

They are likely cooked twice: first they are velveted (meaning marinated and oil-blanched) and then very quickly stir fried to reheat. In more detail, we have three steps:


marinate in a mixture of cornstarch, wine, and egg whites
blanch in oil at a very low temperature (at most 300F/150°C)
make the rest of the stir fry over high heat, and add the meat at the very end of cooking


Unfortunately, velveting is an involved project. It involves an oil-blanch which leaves you with a lot of waste oil. For home cooking, some recipes suggest to replace the oil-blanch with a water blanch.