Marco Polo Sandwich

Ok, I seek a really obscure reference here. In the mid 70's in Pittsburgh I used to get a vegetarian sandwich that I remember to this day. Possibly in Squirrel Hill or Oakland, but I just can't place it now. Anyway, I do remember that it was a Marco Polo sandwich. More than one place carried this. It was miso and tahini spread on good artisan wheat bread. It came with slices of cucumber and then here is where it gets tricky. It had lemon juice and perhaps garlic. Maybe some sprouts or perhaps a tomato. Lovely wonderful memorable hard to eat sandwich. Filled your soul.

I have made variations on this theme for years, so I am really straining my old brain to come up with some details. I wish I knew where I was served this concoction. Also what exactly came on it - uh, standard (did it have onions?). Lastly, if you have any recipe that sounds like this but is called a Marco Polo, I would like to know about it. I am not interested in dips, sauces or dressings. I have recipes for miso tahini spread. I am seeking the Marco Polo, specifically. I know I saw it in some recipe book along the way but lost the book/brain link years ago.