What is the ruling of Islamic law on the food and drink of one who lives with a friend who works in banks and financial institutions that are forbidden by Islamic law, and what should he do?

It is not permissible to work in usurious banks and companies because it constitutes cooperation in sin and aggression, except in cases of necessity that lead to ruin or something close to it. In such cases, it is permissible to the extent of that necessity. As for eating from the wealth of someone whose entire wealth is unlawful, or if it is from the very essence of unlawful money, then it is not permissible. If the money is mixed, then it is permissible with karahah (disapprobation) according to the majority of scholars. We remind the questioner of Allah's saying: "And whoever fears Allah - He will make for him a way out and will provide for him from where he does not expect."