Since 2OI is ignorance about ignorance, any questions at this level are necessarily meta-questions. To address ignorance about ignorance it does seem rather appropriate to pose questions about questions.
Meta Questions
A get-out-of-jail-free approach is to ask a meta question. As the name implies, a meta question is a question about questions (data) and/or questioning (process) and it has the advantage (and disadvantage) of being relatively context-free. A true meta question is only about questioning and the result is not an answer, it is another question.
A simple meta question would be “what questions should I ask you?” Framed exactly like this, the question itself is entirely context-free. However, there must be some reason why the person asking the question is asking it of the person being questioned. One does not randomly walk up to a person in the street and interrogate them so. The questioner and questionee must have some relationship that would itself provide a measure of context. A newbie programmer learning how to set up tests might ask this of an experienced tester. In this case, they would both be aware of some context, even if it is not explicitly included in the question [1].
A slightly more robust meta question might include a measure of context: “…given our testing environment, and thinking back to when you started working with it, what questions should I ask?”
Including this context inevitably constrains the domain of the question; it does run the risk of limiting the possible answers to that domain. In such a case, and if the person being questioned chooses to answer entirely literally, there might be something that occurs outside of the immediate testing environment about which the questioner should know but is not included in the answer. To some extent that possibility is covered by the "....when you started working with it..." qualification, since the person being questioned can use experienced-based judgment to decide if the context needs to be broadened.
A good meta question to close out might be “…is there anything else I should know or should ask?...” If the earlier, more contextual questions, have limited the range of answers this might uncover some additional ignorance.
FOOTNOTES
[1] However, unless the parties take steps to ensure that they do both agree on the context, it's quite likely that some misunderstanding will arise.