Working in a restaurant which sells alcohol
In the Holy Qur’an Allah Ta’la has said:
“O people eat of what is in the earth permissible and good.” (Al Baqarah V168)
Sahl-Ibn-Abdullah has said salvation depends on three things-eating halal, fulfilling obligations and following the Sunnah of the Prophet Sallalahu Alaihi Wasallam. (Mariful-Qur’an P419V1)
Allah (swt) has ordered us to eat from the things which are halal and good for us hence the income we earn should be lawful in order for our sustenance to be lawful.
Regarding your question one should try his best to avoid from working in such environments where alcohol is being served even though he doesn’t have any direct contact with it.
Rasullah (Saw) has cursed 10 things connected with alcohol and one of them is the seller. (Ibn-Majah P242v2)
However if other alternative employment is not possible then instead of sitting at home doing nothing one could work there and give a certain portion of his wages to charity without the intention of thawaab as a certain percentage of his wages will consist of alcohol sales.
Mohammed Tosir Miah
Darul Ifta Birmingham