Dont cook up things. I've never heard anyone insult Christians as a "choora" or not eat their cooked food. Majority of janitorial class in some cities of Punjab is Christian, but there is significant number of them who are cooks and in other professions, and everyone eats their cooked stuff. Again, no one thinks all garbage pickers are Christians (they are actually Pathans in most urban places), yes a significant number of janitorial staff are Christains, which is because the missionaries of pre-Independence specifically targeted certain communities for conversion into Christianity.
Plus, kala is not always used as an insult. In most conversations you just refer to unique attributes of a person just as a reference point. Gora/kala/lamba/mota/patla/ghungralai balon wala/ganja/etc these are just part of our everyday conversations without any ill-intent from any party. There is even an old song "Sanwli saloni" celebrating dark features of a lady. Western teams are often referred to as Gorai even by ex-cricketers. West Indies are often called "Kali andhi" in news etc, not at all in an insulting manner.
We need to learn to appreciate a difference between racism and conversations which are purely rhetorical with no ill-intent.