1. Tofu press or 2 clean tea towels and a weight such as a heavy book | Large, deep frying pan on a high heat | Large plate covered with kitchen paper First, press the tofu using a tofu press or place it between two clean tea towels, lay it on a plate and put a weight on top | Leave for at least half an hour to drain any liquid and firm up before you start cooking Carefully slice the pressed tofu into 1cm-wide sticks and spread them out on a board | Sift cornflour over the top, coating the pieces generously| Use tongs or two forks to turn the pieces and sift over more cornflour until the tofu is covered on all sides | The thicker the better with the cornflour as this coating gives the cooked tofu its crunchy texture Pour enough oil into the pan to fully coat the bottom and heat until it makes the tip of a wooden spoon sizzle | Carefully place the tofu pieces in the pan, with a bit of space around each one (you may need to cook them in batches) | Cook for 5 minutes, turning the pieces every minute or so until they are starting to turn golden brown | Transfer to the plate lined with kitchen paper | Tip away the excess oil in the pan and reduce the heat to medium-high Cut the lemons in half and squeeze the juice into the pan, catching any pips in your other hand (be careful as the pan may spit) | Add the orange juice, sweet chilli sauce, sriracha and soy sauce and bring to the boil | Simmer for 5–7 minutes until the liquid has reduced to a syrupy consistency Add the tofu strips back to the pan and stir until fully coated | Continue to cook, stirring regularly, for 5 minutes and then remove from the heat| Finely slice the spring onion and sprinkle over the tofu along with the sesame seeds before serving