Advice to women who spend most of their time in the kitchen

The believer should be keen to make the best use of his time and not to waste it. Many women, as mentioned in the question, spend hours and hours in preparing various kinds of food. 

The believer should reduce his food intake and his main concern should not be to enjoy whatever he desires of food and other things, even if it is permissible. 'Umar ibn al-Khattaab entered upon his son 'Abd-Allah and found him eating meat, and said, "What is this meat?" He said: "I fancied it." 'Umar said: "Every time you fancy something, you eat it?! It is enough extravagance for a man that he eats whatever he fancies!" May Allah be pleased with them. The Muslim should limit himself to what he needs of food, and not go beyond that. 

Moreover, the time that a Muslim woman spends in preparing food could be used in remembering Allah or reciting Quraan whilst she works. it should also be noted that if her intention when preparing food is sound, namely to serve her husband and children, then that is an act of worship for which she will be rewarded. 

Shaykh Abd al-Azeez Aal al-Shaykh said: 

Her work in her house is an act of worship to Allah, and her doing her household duties and taking care of her children are an act of worship to Allah, so she is in a state of worship, in sha Allah. So she should make the most of the time in order to remember Allah; it is permissible to remember Allah whilst preparing food, praise be to Allah. 

Majallat al-Buhooth, 58/81.