In a large wok or saucepan, heat the 2 tbsp. oil and add the garlic, ginger and spices. Cook over medium heat for a couple of minutes. Add 2 tbsp oil and fill in the aubergine cook for some minutes and stir well. Add the lentils, stock and crushed tomatoes. Stir and put the lid on. Cook on low heat for 25 minutes or until the lentils are soft.