In a large frying pan, heat two tablespoons of the oil, add the onions and soften over a low heat for about 10–15 minutes.
Meanwhile, in another frying pan, heat the remaining oil, add the aubergines and a pinch of salt, then fry on high for five to 10 minutes, stirring often until the aubergine cubes are golden. Set aside.
By this point, the onions should be soft and tinged golden. Add the garlic, fennel seeds, bay leaves and chilli flakes. Fry for a further two to three minutes, then tip in the wine. Bring to the boil and boil until it has reduced by two-thirds in volume (this shouldn’t take more than five minutes).
Last but not least, add the lentils, tomatoes and the browned aubergine cubes. Season and reduce the heat, then simmer for 15–20 minutes until the sauce has thickened a little and the aubergine is buttery soft.
Just before serving, fish out the bay leaves. This ragu is great with soft polenta, pasta or served simply with a hunk of bread.