Heat the oil in large saucepan and sauté the onion for 3-4 minutes. Add the garlic and potatoes and cook for 1-2mins.
Add the sausage, stock and milk. Bring to the boil, then reduce the heat and simmer for 20mins or until the potatoes are tender.
Stir in the sweetcorn and cook for 2-3mins.
Spoon into bowls, sprinkle over herbs and serve.