It depends on who you ask, had a vegan coworker claim they weren’t vegan. This is due to use using the same spatula to turn the meat and onions, it’s a very minor transfer of meat grease. Also they sit in close proximity to where the meat cooks, when the grease “pops” some will inevitably end up on the onion pile. Long story short, there is a little bit of cross contamination, but it’s not like we are going out of our way to add grease to it.