Heat one tablespoon olive oil in a non stick pan. Sprinkle one tablespoon olive oil and salt over the vegetables. Add the yellow zucchini, green and red capsicums to the pan and cook till lightly browned all over.
Add vinegar and toss. Heat the Grill Pan. Place the green zucchini and eggplants in it and cook, turning sides, till lightly browned on both sides. Slice the bread into three slices horizontally.
Cut the mozzarella cheese into thin slices. Place them over the base slice of the bread. Top it with green zucchini and eggplants. Sprinkle some salt.
Place another bread slice over the vegetables and top it with the green and red capsicum and yellow zucchini. Tear a few basil leaves and sprinkle over.
Sprinkle a little salt and place the top slice over. Place the sandwich in the Grill Pan again, drizzle a little oil and cook for a couple of minutes.
Turn over gently, drizzle a little oil and cook for a couple of minutes more. Cut into smaller pieces, wrap in aluminium foil and pack for lunch.