Eating Food Prepared On Non-Muslim Festivals
The shariah directives stay the same whether you live in a Muslim country or a non Muslim country. The food items prepared by the food sellers are for customers whether they take it for a polytheistic purpose or otherwise, as I got it. If your purchase it it is halal and if someone purchases it for a polytheistic purpose and then gives you then it is not halal. The pizza in this case is purchased for a polytheistic purpose therefore it is not halal. If the festival is cultural one not polytheistic then it food distributed in it is halal.