Q) Is it the duty of the wife to cook for the husband and family? Is she sinful if she does not do that and the husband who cook instead (because no food will be available then)?
A) It has been the practice of our mothers, the wives of Rasouloullah Swalallahou Alaihi Wasallam, and also the daughters of Rasouloullah Swalallahou Alaihi Wasallam to cook for their respective families. In the Qur-aan, Hazrat Ibrahim as went to address his wife to cook for some foreign guests. 

 فراغ الى اهله

فجاء بعجل سمين 

And the Quran prescribed the women to stay at home and look after the education of the family. Also Rasouloullah Swalallahou Alaihi Wasallam prescribed the chores inside the house for Fatimah ra and the works in the yards or outside the home to hazrat Ali ra. 

All this indicate that the wife has the duty to cook. But times to times the husband may help her in this task, because Rasouloullah Swalallahou Alaihi Wasallam was helping his wives at home. كان خادم اهله