Pat the tofu dry and press for at least 10 minutes. Cut into small cubes.
Heat 4cm oil to 180°C/350°F in a large frying pan or wok. Dust the tofu with cornflour and chilli powder, add to the oil and fry until crisp on all sides. Cook in batches if you need to then drain on kitchen paper.
Mix the crushed sichuan peppercorns with the sugar and salt. Pour all but 2 tbsp oil away then return to the heat and add the garlic, chilli and spring onions then add the tofu and sprinkle over the seasoning and cook for 2 minutes. Tip out onto a plate and top with coriander and lime. Serve with soy sauce.
Nutrition information is an estimate and will vary depending on the ingredients used.