How do you keep the broccoli from getting soggy?

I'm looking for a good Chinese beef and broccoli stir fry recipe (The way they make it for Chinese take out.) Every time my mom makes it the broccoli gets soggy and is not firm like the broccoli from the restaurants. Also, the beef doesn't taste the same (nor do we know how to make the sauce.) Can anyone give me the recipe for Chinese beef and broccoli stir fry takeout/restaurant style? Please and thank you!