To get the chopping board you have to complete the "cooking hobby"; basically cook a bunch of times to collect all of the equipment..
Once you've done that the all of the chopping boards will be unlocked. The stupid part is there are like 2 or 3 differ ones and you have to get to a certain level to unlock them in the home store. As for the quest part I never encountered this problem, how blizzard
opening up the restaurant went quite smoothly for me, other than the part where cleaning up took a VERY long time