Hello, I cut up some beets, and then some onions, and put them on top of the beets. I closed the container and planned to finish dressing the salad later. It ended up staying in the fridge overnight, without any dressing and the onions were not actually mixed with beets. Would those be considered overnight onions? If so, would it be okay to just remove the onions and keep the rest? I’m also assuming that the rule of overnight onions does not apply to the containers they were kept in overnight. The container remains kosher?
You are right, the halacha of not eating onion that were left overnight will only apply to the onions themselves and the container if fine.