For ratatouille, heat half the oil in a large non-stick frying pan over high heat, add onion, carrot, capsicum and garlic and stir occasionally until tender (3-5 minutes). Transfer to a bowl with a slotted spoon. Add remaining oil and eggplant, stir occasionally until golden (4-5 minutes), then transfer to onion mixture. Add zucchini to pan, stir occasionally until tender (2-4 minutes), then transfer to onion mixture. Add tomato and marjoram to pan, cook until blistered (4-5 minutes) and transfer to onion mixture. Keep warm.
Wipe pan clean, heat oil over medium-high heat, add butter and fish, skin-side down, cook until golden and crisp (3-4 minutes), turn and cook until cooked through (2-3 minutes), then serve hot with ratatouille and lemon.
This recipe is from the July 2011 issue of Australian Gourmet Traveller.