My daughter cut an onion with a meaty knife (not used within 24 hours) on a milky board (not used for 24 hours; in general used for cutting onions with milky knife). She then put the onions in a meaty pan and started to heat them up. What is the status of the pan?

Shalom, Firstly let me apologize for the delay in answering your question. We have had some technical problems with the site, and I only received your question today. There is a debate about cutting "sharp" or spicy foods with a meat knife on a milk cutting board (see Chachmat Adam 56,2). However as both the knife and the board were not ben-yomo, and due to other factors, we rule that all the utensils are kosher (see Daat Torah ibid). Blessings