Yes, I've done it on two separate occassions. It is free, but it might be at 3:45 or 4:00, depending on the day (I think Boma opens at different times on different days, and they want to make sure the tour is over). Yes, it's free, including the food samples. Both times was the same routine-first, we sat at the Jiko bar and show kitchen, eating the Taste of Africa appetizer they gave, having the different spices explained to us and a little about the resturant in general. Then, we went over to Boma and shown all the different offerings (which were also explained) on the buffet. Both times we got samples at the buffet, different offerings, depending on what was requested or the tour guide was anxious for us to try. Please note, there's a similar tour at Sanaa. However, at Sanaa, there's more of an explanation of the culture surrounding the resturant. However, at the end, the chef prepared me an appetizer with three dips and three breads to try, while she also explained the different ingredients used. Both were great tours!
