Heat a large skillet over a medium flame. Add the eggplant and cook 1-2 minutes per side, until soft. Remove from heat.

Butter each slice of bread and sprinkle them with garlic powder. Flip 4 slices of bread over (so the buttered side is down) and top each with one slice of cheese and a quarter of the eggplant. Spread the sundried tomato pesto over the eggplant and top with the remaining cheese. Top with the remaining bread (buttered side up).

Cook sandwiches over low heat for 3 minutes on each side, or until bread is golden brown and cheese is melted. If necessary, place a cover over the pan for the last 3 minutes to help the cheese melt.