Make up 1.5 litres vegetable stock using the stock cubes. Heat the olive oil in a large saucepan, add the onion, carrots and celery and cook for about 8-10 mins until beginning to soften but not colour. Add the garlic and ginger and cook for a few mins more. Pour over the hot stock and simmer for 10 mins, then add the chicken and cook for a further 10 mins.
Meanwhile, bring a medium saucepan of water to the boil, add the noodles and cook for 3 mins until tender. Drain well and refresh under cold running water.
Add the spring onions, sugar snap peas and cabbage to the vegetable and chicken broth, and simmer for 5 mins.
Divide the noodles between bowls and ladle the broth over the top. Flavour with the low-salt soy sauce, if you like.