Take a 12-inch (30cm) oven-proof dish or skillet and pour in the jar of tomato sauce. Spread evenly around the base of the pan.
Slice the aubergines, tomatoes and courgettes into approximately 1mm thick coins. Arrange the sliced vegetables in an alternating pattern, spiraling around the pan, start from the outer edge and work towards the centre.
Brush the vegetables with olive oil and scatter over the dried oregano, salt and pepper.
Cover the dish with foil and place in the oven to bake for 30 minutes. Remove the foil and transfer back to the oven to bake for a further 20 minutes, or until vegetables have softened.
Sprinkle the ratatouille with Dubliner 3 Cheese Blend to serve.
