Wash and dry seafood, then season seafood, potatoes, aubergine, and tomatoes with salt, vegetable oil, sugar, and spices before refrigerating.
Heat mustard oil and sizzle cardamom, peppercorns, bay leaves, onion seeds, and fennel seeds.
Add onions and cook for 10 minutes until golden-brown.
Fry turmeric, chilli powder, and cumin for 1 minute before adding tomatoes and chillies for 3 minutes.
Stir in fish stock, salt, and sugar, then simmer for 10 minutes.
Add coriander and lemon juice, cook for 2 minutes, then sieve the broth and stir in ground cardamom.
Sear the seafood mixture, excluding lobster and squid, in a hot pan for 2 minutes.
Add lobster for 1 minute, then add squid and cook for 2 more minutes until done.
Transfer seafood to a bowl, garnish with coriander cress, pour over the warm broth, and serve with rice.