Since you were looking for the fiqhi ruling on this issue, we saw it necessary to ask your question from the offices of the grand maraje’; this is what we received in response from them:
The Office of the Grand Ayatullah Sistani:
As long as your work has nothing to do with alcohol and other haram things, and you only work in the section that has to do with halal things, it is permissible.
The Office of the Grand Ayatullah Makarem Shirazi:
Since it is hard for you to find another job, you can keep this one.
The Office of the Grand Ayatullah Safi Golpaygani:
Serving alcohol and other haram foods to others is haram and getting paid for it is also haram.
Ayatullah Hadavi Tehrani’s response:
If you work in the halal section of the restaurant, it is permissible. If finding a job other than one in the haram section of the restaurant or the section where both haram and halal are mixed is very hard for you, it is okay to work there no more than necessity calls for.
For further information, refer to:
3- Being firm in belief and faith, Question 1812 (website: 3204).
This question does not have a detailed answer.