This is a great summer dish. I made it on the grill pan on the stove but I think on a hot day it would do nicely on the outside grill.
Eggplant Mushroom Sandwiches
1 eggplant, sliced in 1/4 in slices
4 portabello mushrooms, stem removed
1/4 red onion, sliced thinly
4-6 lettuce leaves
1/4 c mayonnaise
Reduced Balsamic vinegar
4 slices bread or buns
While grill pan (or grill heats) sprinkle eggplant slices with salt/pepper. Brush lightly with olive oil. Grill eggplant until softened but slightly firm. Set aside. Grill mushrooms caps. Sprinkle with salt/pepper.
Assemble sandwiches. (I did open-faced sandwiches): Toast (if desired bread or bun). Spread 1T of mayonnaise on each sandwich. Place one slice (or 2 depending on size of eggplant) on top of mayonnaise. Stack mushroom, onion ring, and then lettuce. Drizzle with balsamic reduction. Serve.
I think once zucchini is in season that might also make a nice addition to this sandwich.