Roppongi, I will admit, is an area of Tokyo I try to avoid with all my might. Nightclubs and expensive restaurants and bars are not so interesting to me these days. (Those wild days are long over, although they were undeniably fun at the time!) It's the kind of ex-pat scene that doesn't suit me, really, although I do occasionally hear of interesting things happening...like the market.
And it was amazing! An excellent selection of organic rice, vegetables and even some fruit in a market not as big as the UN University one, but also not entirely as organic and fair trade as the Earth Day Market, either. It was well worth the journey. And you can read my full review of it at Summer Tomato!
10am to 2pm
Go to Tameike Sanno Station and head for Exit 13. As you come up the steps to street level, go straight about five minutes always keeping the double-decker highway on your right. After you cross a small "street" (really the driveway for the big hotel there) look for a set of stairs and an escalator on the left. Head up those to the courtyard there, and get ready to shop!