Kads, the first thing that popped into my head reading your recipe idea, was it reminded me of an inside-out Panzanella.
One of my fave summer picnic sammies is Ensalada Caprese on crusty Italian bread (basil, fresh mozzarella, ripe tomatoes, s&p, evoo & vinegar) - and a side of marinated mushrooms, cold potato or cold mac salad etc.
I was at Quizno's the other day (don't laugh, but I like their whole wheat bread & sammies), & they were putting together a chopped salad on flat bread that looked really good. May put that tog at home. That reminded me of a recipe on Williams-Sonoma's site for an eggplant (roasted red pepper, onions etc - from memory) on flat bread. How 'bout a caponata sammich?
My cucumber, tomato, red onion, red wine vinegar & oil salad is made up in the fridge -- if I can p/u some focaccia, would like to give your idea a go -- maybe add some kalamatas & maybe cold asparagus. A guac salad is another thought. Lots of possibilities. Thanks for sharing your idea!
I'm on my way to find a bib