Prepare Eggplant: Peel the eggplants completely and cut them into cubes. Sprinkle salt on the eggplant cubes and mix well. Place them in a strainer under running water and leave for 10 minutes to remove excess water.
Prepare Vegetables: Roughly cut onions, green bell pepper (seeds removed), and optional hot pepper. Cut tomatoes into cubes.
Sauté Onions and Peppers: Heat 1/4 cup olive oil in a frying pan over medium heat. Add onions, green bell pepper, and hot pepper. Sauté gently without browning for about 3 minutes, stirring occasionally.
Cook Eggplant and Vegetables: Add the drained eggplant cubes to the pan. Stir and cover the pan to cook the vegetables in their steam and oil. Stir occasionally and continue cooking until the eggplant and vegetables are wilted and softened.
Add Tomatoes: Add the cubed tomatoes to the pan. Stir and cover again. Cook on low heat, stirring occasionally, until the tomatoes release their juices and melt into the mixture.
Mash the Mixture: On low heat, mash the cooked vegetables gently by hand or with a spoon to create a coarse consistency. Avoid using a blender or grinder to keep texture.
Add Seasonings: Crush garlic cloves with a pinch of salt and add to the pan. Add 1/2 tablespoon cumin and 1/2 tablespoon paprika. Stir well on very low heat until all ingredients are well combined and heated through.
Prepare Tahini Sauce: In a cup, mix equal parts freshly squeezed lemon juice and water (about 1 tea cup each). Add 1 cup tahini and a pinch of salt. Whisk vigorously until smooth and loose but not stringy.
Serve: Transfer the eggplant mixture to a serving dish and shape as desired. Pour the tahini sauce evenly over the top. Garnish with chopped parsley, a drizzle of olive oil, and crushed or broken walnut pieces if desired. Serve warm or at room temperature with bread.