What is the landlord required to cover for flooding in the kitchen?

You likely are entitled to compensation under the law, but unfortunately, you cannot take it by withholding the cost of your meals from your rent. A landlord is liable for additional costs or other damages suffered by a tenant when the landlord cannot provide possession of the tenant's full rental unit and/or provides a rental that is not fit for its intended purpose--i.e. residence--such as through the lack of a kitchen. From what you write, your landlord may have breached or violated the lease (you're not getting what you paid for) and/or the implied warranty of habitability (the premises is not fit for  residence).

However, the only time a tenant may lawfully withhold a portion of rent is when the landlord has failed to make necessary repairs (ones required for habitability) after notice from the tenant and a chance or opportunity to make said repairs; when that occurs, the tenant may pay to have the repairs made, and deduct the cost thereof from the rent. Howeever, that is not the situation you describe--buying meals is not making repairs--and so you do not have access to this "repair and deduct" remedy.

Instead, to get to the money to which you may well be legally entitled, you would have to sue the landord to recover it (assuming he/she does not voluntarily give you compensation or a rent credit), which is likely not economically worthwhile. Unfortunately, not every time you are entitled to compensation is there an effective way to receive it.