Oh my, this sounds wonderful! The old fashioned tomato sandwich with nuttin' but mayo is a comfort food from childhood, for sure. What about with fresh mozzarella and fresh basil?
I love hummus. Especially MY hummus...but I am with Zen that it doesn't belong even close to my tomato sandwich.
I've a friend who loves PB, tomato and mayo sandwiches... now that just doesn't sound good but like she says, don't knock it till you try it