Slice the beef thinly against the grain, then mix it with 1 tablespoon soy sauce, 1 tablespoon oil, 1 tablespoon cornstarch, and baking soda if using. Allow the beef to marinate for 10 minutes.

Combine chicken stock or beef stock, Shaoxing wine or dry sherry, 2 tablespoons soy sauce, dark soy sauce, brown sugar, and 1 tablespoon cornstarch in a bowl, whisking until the mixture is smooth.

Pour 1/4 cup water into a skillet over medium-high heat, add the broccoli florets, cover, and steam for about 1 minute until the broccoli is bright green and slightly tender. Remove the broccoli and set aside.

Heat 1 tablespoon oil in the skillet until very hot. Add the marinated beef in a single layer and sear briefly until browned.

Add the minced garlic and ginger to the skillet and cook briefly until fragrant, then return the steamed broccoli to the pan.

Stir the sauce mixture again, add it to the skillet, and cook while stirring until the sauce thickens and evenly coats the beef and broccoli.

Serve the Chinese beef and broccoli stir fry immediately.