1.Heat half the oil in large frying pan; cook fish, skin-side down, until browned. Turn; cook other side until browned. Remove from pan.
2.Heat remaining oil in same pan; cook onion and garlic, stirring, until onion softens. Add curry paste; cook, stirring, until fragrant. Add the water and tomato; bring to a boil. Reduce heat; simmer, uncovered, 5 minutes.
3.Return fish to pan; simmer, uncovered, about 5 minutes or until fish is cooked through. Serve vindaloo sprinkled with coriander leaves and, if desired, steamed basmati rice, pappadums and raita.