What is the ruling on eating the food of Indian Sikhs and sharing their dishes, and working with them in one place?

It is permissible to eat with a disbeliever, whether Christian or otherwise, at the same table or from the same dish, provided that the food is lawful (halal (definition)) and that there is no unlawful food or drink on the table, and that no other abomination accompanies the meal. The disbeliever is not physically impure; rather, their heart and belief are impure, as Allah Almighty says: "Indeed, the polytheists are impure." Similarly, it is permissible to work with them in the same place if the work is lawful, while striving to invite them to Islam.