1. Peel the onion and cut off only the top cap.
2. Cut the inner onion loose and scoop out the inner layers of onion, leaving a rim of 2 layers of onion. Use a bulb cutter or sharp grapefruit knife to do this. Save the loose pieces of onion.
3. Bring water to the boil in a large pan. Boil the hollowed-out onions for 10 minutes until tender. Let them drain, then cool.
4. Chop the onion pieces and fry them in a large frying pan in hot oil until crisp and brown. Remove from the pan and save to garnish the dish with.
5. Preheat the oven to 180 degrees.
6. In the same pan, briefly fry the garlic and ginger. Stir in the massala and fry for 1 minute. Spoon in the carrot and peas and fry for 10 minutes. After 5 minutes, add the aubergine and the cinnamon stick. Stir the tomatoes and juice into the vegetables and simmer for 5 minutes.
7. Arrange the onions in a deep baking dish and fill the onions with the massaga vegetables. Spoon extra sauce around the onions in the dish. Cover with aluminium foil. Bake the dish in the preheated oven for 25 minutes.
8. Before serving, sprinkle the onions with fresh coriander and the fried onions. Enjoy your meal!