An Ashkenazi has an oven baking dish that is metal and the inside is Teflon. They have used it for meat but a long time ago. They were in middle of self cleaning the oven, it was almost finished and someone put dairy in the dish and lowered the temp to the oven and then put it in the oven. Whats the status of everything?
ב"ה Shalom My understanding is that the oven was hot enough to bake or roast in, and the Teflon dish became hot enough. Therefore the Teflon baking dish, since it has now absorbed both meat and milk is now NOT kosher. Since, the Teflon baking dish is used without fluids, it cannot be made kosher in boiling water, and neither by "libun" since it would ruin the dish. The food that was made in the dish, after the fact, however, may be eaten with other dairy , since the "meat" absorbed in the baking dish is now tasteless since more that 24 hours have passed since the last of use for meat. All the best