Cut the eggplant into about 1 cm thick slices, brush both sides with a little oil and season with garlic powder. (If I wasn't using halloumi in this recipe I would also sprinkle a little salt over the eggplant). Ensure the pan is hot before you place the eggplant slices in it. Then lower the heat and cook the slices for about 5 minutes on each side. The trick is to cook it long enough so it's tender inside while nicely browned on the outside. That's why it's important to grill the slices over a fairly low heat.Once your eggplant slices are tender you can increase the heat towards the end of cooking to get nice brown markings (this may not be needed).
Once you have grilled your eggplant lightly grease and heat up the griddle pan to prepare the halloumi cheese. Grill the halloumi over a medium heat for about 2 minutes on each side. The cheese will soften as it heats up so be careful turning it over - it may tear.
Assemble the sandwich immediately (the halloumi will harden as it cools) by creating layers of salad leaves, eggplant, halloumi and tomato slices. Add a dollop of your favourite sauce (see Serving Suggestions below), cover with the other bread slice and enjoy!
Do not overcrowd the griddle pan. Fry the eggplant over a fairly low heat so it has time to cook through without becoming brown too quickly. Grill the halloumi briefly over a medium heat.
Prepare the halloumi when you are ready to assemble the sandwich. Grilled halloumi should be served immediately as it becomes tough and chewy as it cools.
What bread to use: Any! Use burger buns, ciabatta bread, or regular bread and even wraps to make your sandwich.