To make the sriracha yoghurt, combine all ingredients in a bowl. Set aside.
Preheat oven to 120°C. Place flour, milk and eggs into a medium bowl. Season with salt and pepper. Whisk until smooth. Add prawns, corn kernels, green onions, chilli and coriander. Stir until well combined.
Heat oil in a large non-stick frying pan over medium heat. Using about 1/4 cup mixture per fritter, cook fritters in batches, for 2-3 minutes on each side or until golden and cooked through (add extra oil to the pan if necessary). Transfer to a baking tray. Keep warm in the oven.
Serve the fritters with sriracha yoghurt, lemon wedges and coriander leaves.