In a large pan, put the red lentils, chopped tomatoes, bay leave, or curry leaves, and turmeric together with 400 ml (2 cups) water and bring to a boil. Turn the heat to low and simmer for 20-25 minutes until the lentils are cooked. Remove the bay leave.
Add the aubergine/eggplant chunks and onion to a baking tray and season with salt and ground black pepper. Bake in the oven for about 25 minutes.
Put all the cooked aubergine/eggplant, and onion chunks in a frying pan and add the garlic and all the spices, except for the garam masala. Cooks for 1 minute until fragrant.
Add the cooked aubergine/eggplant spiced mix into the red lentil mix and stir together. Add another 200 ml (1 cup) water and simmer for 15 minutes, stirring regularly. Add the garam masala and cook for another minute. Add the chopped coriander if using, and serve with naan bread or rice.
Notes
Leftovers will keep well in the fridge for up to 3 days.