5 Wishelin Starred venue: What are the chances of a Prep recipe in profit box?

Sansa

So, when a venue has hit 5 Wishelin stars, there is a chance to get a prep dish of that venue, but what are your chances so far?

Karissa

I have all 5 wishelin stars for PP, I've had it for about a couple months and I've gotten prep dishes about twice. Honestly it isn't worth it in the amount of gold you end up spending.