For the Kesra: In a small bowl of 1/4 cup warm water, stir in the yeast and sugar. Stir lightly until yeast begins to dissolve. Allow mixture to stand until it begins to bubble, about 10 minutes.
In a standing mixer bowl, put flour and 1/3 cup of cornmeal. Make a well in the center and add yeast mixture, salt, and melted butter. Knead the bread and gradually add remaining warm water until dough is smooth and elastic.
Sprinkle baking sheet with olive oil and then dust with cornmeal. Separate the dough into 2 balls of equal size and sprinkle sesame seeds evenly over the loaves and flatten into round circles. Cover the doughs with a clean towel and let rise in warm place until doubled in size, about 1 hour.
Preheat oven to 425 degrees F. Prick the top of each dough with a fork all over. Bake for 10 minutes.
Lower heat to 375 degrees and bake an additional 15 to 20 minutes or until crusty and golden brown.
For the Vegetables: Preheat oven to 375 degrees F.
Cut the eggplant into 1/4-inch round slices and sprinkle with salt, let sit in colander for 10 minutes until bitter juices are extracted.
Rinse the slices, and toss with olive oil, salt and pepper. Roast the eggplant slices until they are tender and a little crisp.
Mix flour and cornmeal and season with spices, to your taste. Coat each tomato slice with mixture and heat butter in heavy skillet (preferably cast iron). Add the tomatoes and cook until golden brown on both sides. Drain on paper towels.
For the Harissa: Process all the ingredients in a food processor. Season, to taste, and reserve in a small bowl.
To assemble sandwich, spread 2 slices of Kesra with Harissa spread. Place a layer of eggplant, then tomatoes on bottom slice. Curly lettuce is optional. Top with other slice of bread.