Can I eat NON HALAL meat cooked by christians? Non halal as it’s slaughtered by machinery in a factory farm but the farm is from christians? Allah says in Quran that their food is halal for you? Does that make that meat halal? Please advise

One of the conditions for meat to be halal is that the one slaughtering the meat is a Muslim. The ayat you mentioned is referring to the non meat items such as vegetables, fruits and grains as was explained by out 6th Imam (as) in explaining this verse.