Begin by preparing all of the ingredients.
In a large pan, add a dash of oil or water with the onions and cook for about 5 minutes, with a lid, until beginning to soften.
Add the diced garlic, mushrooms and grated carrots and sweet potatoes and stir.
Next, add the rinsed green and red lentils.
Then add the tomato passata, tomato paste and 4 cups of water. Stir everything together, replace the lid on the pan and bring to the boil. Turn the heat down to the lowest setting and leave to simmer for 30 mins. After 30mins, take a look at the ragu and add up to 2 more cups of water to thin the sauce if needed.
Whilst the ragu is cooking, spiralise the courgettes and leave to one side.
Once the ragu is ready, season with ground black pepper and sea salt to taste, stir through the chopped, fresh basil leaves, saving a few for serving.
Place some of the courgetti into each serving bowl with a large spoonful or more of the ragu. Add a few fresh basil leaves and serve warm.