Heat oil in wok. Add carrot, capsicum, mushrooms and onion and stir-fry for two minutes or until half cooked. Add tofu, and stir-fry for another one minute until heated through.
Add soy sauce and chilli sauce and cook for half a minute. Add stock and stir. Mix the cornflour with one tablespoon of water and add and cook till sauce thickens.
Add in celery, salt and peppercorns and toss. Stir in roasted peanuts and serve hot.