Marinate the tofu in a bowl with 1 tbsp of the light soy sauce, 1 tbsp of the sweet chilli sauce and a squeeze of lime. Allow to sit in the fridge for at least an hour.
Heat 1 tbsp of the groundnut oil in a large wok until searing hot. Add the garlic and tofu, and cook over a high heat for 2-3 minutes until the garlic becomes fragrant.
Heat the remaining groundnut oil in the wok, add the broccoli and a splash of water and cook over a high heat for 2 minutes, stirring occasionally. Add three quarters of the spring onions, the pepper and mange tout and cook for 2 minutes.
Return the tofu to the pan and stir in the butternut boodles. Stir-fry for 1 minute, then add the remaining soy sauce and chilli sauce. Add a squeeze of lime and drizzle over all the sesame oil. Divide between four warmed bowls, scatter with the remaining spring onion and serve straight away.