Heat the oil in a large saucepan and cook the vegetables and ginger for 7–8 minutes until slightly softened. Add the chilli flakes, tomatoes, hot stock and chickpeas and bring to the boil. Reduce the heat and simmer gently for about 10 minutes until the vegetables are tender.
Use a hand-held blender to blend until smooth. (Alternatively, if you don't have a blender, serve it as a chunky soup.) Season to taste, then ladle into mugs to serve.