Heat the oil in a wok or large, deep frying pan, preferably non-stick. Add the onion and stir over a medium heat for 7–8 minutes until softened. Stir in the curry paste and cook for a few more seconds.
Add the baby corn cobs and stir to coat in the curry paste. Gradually add the stock, soy sauce and coconut milk. Bring to a gentle simmer and cook for 1 minute. Carefully stir in the remaining vegetables and tofu cubes. Bring back to simmering point, then cover and cook for 5–6 minutes until the vegetables are just tender.
Add the noodles to the vegetable mixture and cook, stirring, for a further minute. Stir in the chopped coriander and serve straight away.