Heat a little oil in a medium saucepan and add onion. Cover and cook on a medium low heat, stirring occasionally for 5-10 minutes or until onion is soft.
When the onion is soft, increase the heat to medium high, add the sausages and cook for a few minutes until browned.
Add the lentils. Stir for a minute.
Add red wine and the stock. Stir well then simmer for 15-20 or until the stock is absorbed and the lentils are tender and oozy. If it gets too dry before the lentils are cooked, add a little water.
Add cheese and stir until combined. Taste and season. Serve with extra parmesan shaved over.