Pre-heat the oven to 200°C/ 400°F/Gas Mark 6 or Fan 180°C. Brush Cauldron sausages with half of the oil and cook on the middle oven shelf for 20 minutes
Meanwhile bring a pan of water to the boil and cook the potatoes for 12-14 minutes or until soft.
Pre-heat the remaining oil in a saucepan and cook the onion for 5-7 minutes or until softened. Add the garlic and herbs and continue to cook for a further 1 minute.
Add the tomatoes and peppers to the pan and simmer gently for 6 minutes.
Drain the potatoes and add them to the pan along with the sausages then simmer gently for 5 minutes. Season to taste. Scatter over the olives and torn basil leaves.