The CAFE is the place where we have open-ended discussions. Originally, the Café housed just open-ended questions where participants explored the grey areas of a particular topic. Now, the café consists of forums, cases, as well as open-ended questions. The designers supply responses from subject-matter experts and scoring rubrics to enable participants to grade themselves.

Examples:

We provide a video introducing two business decisions: Should you take Project One or Project Two. The video includes the financial data for each project and the background information on how you got to this decision point. You must upload your decision and why you made it. Once posted, you can look at the other participants’ decisions as well as the subject-matter expert’s response.
Alternatively, we could have a simple Café item. We might ask the participants to post their background information and reason for taking the course in the intro module. As the instructor, we can respond and comment at will.

Tips:

Be sure there is no right or wrong answer. Or, if there is, be sure it is nuanced. The key is you want participants to really think through the question deeply.
Provide an expert response or perspective. This is your opportunity to indeed provide the "right" answer-- meaning the answer you would like participants to think of as they explore this topic.
Don't correct unless it is a case study and there is an overtly bad direction (still a bit of grey). But avoid correcting.
When possible, comment on their comments. Add value.