I don’t know where you are and if there is a kosher resturant available. Assuming there is I would quietly go to your boss and explain and ask if it could be held there. If you do it with grace there is a decent chance he will say “Sure no problem”.
Back when I was living in Boston I was helping to organize a Computer User group meetup. I was the only one who kept kosher out of the crowd but when I suggested a Kosher place no one had any problems holding it there. (I think one person asked if there was a vegetarian option which there was)