Dust prawns in rice flour and deep fry in batches for 3 minutes until golden and crispy. Drain on paper towel. While still hot, toss in lemon chilli salt and serve with sumac mayonnaise and a side salad.
Lemon Chilli Salt: Combine lemon, salt and chilli flakes in a bowl, mix well.
Sumac Mayonnaise: Combine whole egg mayonnaise, garlic powder, ginger and sumac, in a bowl.