Here's how the master chef in a classy Chinese restaurant I worked in tenderised all chicken using baking soda. The amounts and timings need to be precise or you risk failure. The amounts below are for ONE chicken breast; multiply the amounts for more than one. Keep the timings the same as below irrespective of how many breasts you are using. This method gives moist, tender shiny chicken.
1/2 teaspoon baking soda
Place in a bowl with 1/2 teaspoon of corn starch and I teaspoon of Chinese rice wine. Cover and refrigerate for 15 mins.
Then use in recipe as per usual. Don't overcook; it will take 30 secs to 1 min only in a very hot wok.