You can still save a broccoli plant that has bolted early by harvesting the head. Side shoots typically grow after a couple of weeks. Aside from that, if you’ve caught it early you can try your luck with simply pruning off the flower buds. However, there’s no guarantee that your broccoli plant will stop bolting. However, broccoli plants that have bolted early usually don’t regrow well. Hence, you may be better off removing the plant entirely and replanting a new one.