1. For the crazy water, put the tomato, garlic, parsley, chilli, extra virgin olive oil, sea salt and 750ml (3 cups) water in a pan. Bring to the boil, reduce to a gentle simmer, cover and cook for 45 minutes. Remove the lid, increase the heat and cook until the volume has reduced by half.

2. For the beer batter, add enough flour to the beer to give the consistency of pouring cream. Mix it with a chopstick (it shouldn't be completely smooth). Allow to stand for 10 minutes in the refrigerator, then add some ice cubes – the batter turns more crisp in the hot oil if it is cold.

3. Heat the oil in a large frying pan or deep-fat fryer to 180°C. Dip the flathead fillets in flour seasoned with salt and pepper, then into the beer batter, shaking off any excess, and gently put into the oil. Don't try to cook all the fish at once, do it in 2 or 3 batches. Cook for about 5 minutes, or until the batter is golden brown, then remove the fish with a spider or slotted spoon and drain on paper towels. Keep warm while you cook the remaining fillets.

4. Divide the crazy water between 4 bowls. Place fish fillets on top. Sprinkle with sea salt and give a good grind of pepper, then serve with a lemon wedge.

Note: Known as "acqua pazza" in Italian, crazy water gets its name from the addition of the tomatoes and chilli to make the water "crazy". Try Adam Liaw's acqua pazza recipe here.

Find more of Neil Perry's recipes in the Good Food Favourite Recipes cookbook.