Is it permissible for me to take money from my employer for my food and drink if it is one of the conditions of my employment, but I consume them outside the premises?

There is no harm in the employer undertaking to provide food and drink for the worker during work. It is permissible for the worker's food alone to be the wage, or for it to be combined with money.

As for the worker eating outside the premises and returning with the cost of what he ate to the employer, the reference in this regard is the contract between you and the conditions it contains, for the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions." If the condition stipulates that the employer pays for your food and drink if you purchase it yourself, then you have the right to take the cost. If the condition stipulates that the worker is entitled to a limited allowance for food and drink, then he is only entitled to the agreed-upon allowance. If the condition stipulates that the employer is responsible for bringing and providing food and drink to the worker, then you have no right to take the cost of what you bring yourself unless the employer agrees. If the condition is unclear, then refer to the labor system and its regulations, and you can ask the employer. Do not take anything from his money except according to the contract or with his willing consent.