You can blanch and freeze when florets first appear, if you can't keep up with the florets when they develope. If flowers develope, try cutting them off and see if the leaf axils develope florets. Keep on munching the brocs, as it is good for you. I wish we had room for it ,as we grew it in the past.

Do you mean they went to flower before producing any reasonable heads? If so, then the problem with broccolis and caulis is that any setback when they are growing, such as lack of water or a cold snap, will cause premature going to seed. Try using trickle irrigation if you are out at work during the day or don't have time to water on a very regular basis. They also like to be well fed, so don't be mean with the fertiliser. I use a good handful of organic seaweed based fertiliser right around the base of the plant. This is economical as it's a waste to throw fertiliser every where when you only want to feed the plant, not the weeds around them!