Interesting thing to know:
If you intend to cook broccoli or other cruciferous veggies like cabbage, cauliflower, etc., and have time to cut it up early, let at least 40 mins pass before cooking. It will be more nutritious than if it is cooked right after being cut up. At the 40-minute mark, the sulforaphane in it (which is so good for us re: brain health, liver health, cancer fighting, diabetes, nasal allergies) will have already been made, in the same way it would have been made in our digestive systems if we had chewed up the raw veggie. This way, cooking won't stop the process, and it will be just as good for us as if it was raw.
Dr. Greger calls this the "Hack and Hold" or "Whack and Wait" technique.
Purchased frozen cruciferous veggies, btw, are almost always blanched immediately after chopping, so usually wouldn't provide any sulforaphane. Already cut-up bags in the produce aisle would be a good bet to already contain it, though.