Mix 2 tablespoons of the Indian seasoning together with the flour. Coat fish fillets in flour mix and set aside. Heat the oil in a medium frying pan and sauté the onion until just tender. Season with salt and pepper and set aside. Cook the fish in the same pan, adding a touch more oil and the butter, spooning the oil and butter over the fish. While fish cooks, mix the mayonnaise with the coriander, lemon zest and remaining Indian seasoning. Once the fish is cooked, assemble the burgers. Spread all the bun halves with the mayonnaise, then place onion on the bases, top with lettuce, fish, beetroot, then tomato and place the tops on. Serve with homemade fries if desired. SIMON SAYS You can use other flavourings, such as my Simon Gault Home Cuisine Italian seasoning, and play around with the fillings to suit your taste – pickles, for example, go well.