In a large saucepan or medium sized pot, heat olive oil over medium heat. Add onion and season with salt and pepper. Saute until the onion begins to turn translucent and brown slightly, about 5 minutes. Add sliced garlic and cook until fragrant, about 2 minutes. Add Aleppo pepper, tomato paste, and saute for 1 minute more. Add tomatoes and cook until they are beginning to break down, about 10 minutes. Stir brown sugar, lemon zest, vegetable broth, eggplant, raisins, and cinnamon. Season with salt and pepper.
Bring the mixture to a boil and reduce to a simmer, stirring occasionally until eggplant is fully cooked and raisins are plump, about 20 minutes. Once the eggplant is cooked, remove from heat and stir in reserved lemon juice. Serve topped with feta, mint, and nuts with couscous, pita, or rice.