Pak Choi bolting

Have noticed recently my pak choi is starting to produce flower buds. Is it still ok to harvest and eat it? I was hoping it would get a bit bigger but I presume once it has decided it wants to seed then it's game over as far as increasing the plant size is concerned?

My tatsoi has bolted, and some of the spinach is going the same way.  If it's too far gone the chickens would love it, but if it's just starting to set seed then I'd eat it. I am using bolting spinach in tonight's pasties and the basil that was beginning to run to seed was pestoed