- For the dijonnaise, pulse egg yolks, mustard and vinegar in a food processor to combine.
- With the motor running, slowly pour in oil until it is incorporated. Add water and lemon juice, and pulse to combine. Season to taste.
- For the chickpea fritters, half-fill a deep saucepan or a deep-fryer with vegetable oil, and heat to 180˚C.
- Process remaining ingredients in a food processor until smooth. Strain through a fine sieve.
- Transfer mixture to a large saucepan and place over high heat. Whisking constantly, cook until the mixture is smooth, thick, and shiny, and bubbles start to appear on the surface. Remove from heat.
- Working quickly, place heaped tablespoons of the mixture onto a large tray lined with baking paper.
- In batches, deep-fry fritters for about 2 minutes or until golden and cooked through.
- Keep warm in a low oven.
- For the barramundi burgers, heat oil used for fritters to 180˚C.
- Combine flour and sparkling water in a bowl. Set aside until needed.
- Heat olive oil in a frying pan over medium-low heat. Cook eschalot for 2 minutes or until soft. Add lemon zest and remove from heat. Set aside to cool.
- Add barramundi, cooled eschalot mixture, breadcrumbs, parsley and salt to a large bowl, and mix to combine.
- Divide mixture into 6 portions, then shape into patties.
- Dip barramundi patties into batter and coat evenly. In batches, carefully lower patties into oil. Deep-fry for 5 minutes or until cooked through.
- Place patties in buns, top with Dijonnaise and rocket leaves. Serve with chickpea fritters and Dijonnaise.