Prepare vegetables: Dice one medium onion, one tomato, and optionally one hot pepper. Slice eggplants, potatoes, zucchini about 1 cm thick. Seed and slice peppers into rings. Slice the second onion for layering.
Cook onions and chili: Heat 3 tablespoons vegetable oil in a frying pan over medium heat. Add diced onions and chopped hot pepper. Stir until onions wilt and become transparent.
Cook minced meat: Add 400 grams minced meat to the pan. Break up the meat and stir with onions and chili until the meat changes color and its water evaporates.
Add spices and tomatoes: Add 1/2 teaspoon cinnamon and 1/2 teaspoon seven spices. Immediately add diced tomatoes. Stir and cook covered on low heat for 5 minutes, turning occasionally until tomatoes wilt and form a sauce.
Assemble vegetables in tray: In a cooking tray, layer the sliced eggplants, potatoes, zucchini, peppers, and onions. Arrange remaining vegetables evenly.
Prepare sauce: Mix 3 cups water with 2 tablespoons tomato paste, salt to taste, and a pinch of black pepper until smooth without lumps.
Add sauce and cook: Pour the sauce over the layered vegetables in the tray. Add more water if needed to cover the vegetables. Cover the tray and cook on high heat until boiling, then reduce heat to low and simmer covered until vegetables are tender (about 10 minutes). Check doneness by piercing potatoes with a fork.
Serve: Once cooked, turn off heat. Serve the musabkha warm, optionally with bread, onions, or additional hot pepper.