The great thing about the roasted veggie sandwich is that it can be created with any veggies on any sort of bread. Simply roast the veggies (eggplant, zucchini, peppers, etc.), assemble your sandwich, then stick the whole thing in the oven for a few minutes to melt the cheese. This version here was topped with pesto mayo, but when I have more time I skip the mayo altogether and marinated the veggies in an herb-based sauce or Italian dressing. The marinade makes the veggies so flavorful no additional spread is needed. Instead of the flatbread I have used a baguette, a potato roll, or regular bread- whatever is on hand.