In a large saucepan or pot, heat 1 tablespoon of the oil over medium heat. Add the cumin seeds and fry for 30 seconds, or until they darken in color slightly and are fragrant.
Add onion and sauté until tender, 5 to 7 minutes, then add the garlic and sauté for 30 seconds to 1 minute more, until tender. Finally, add the curry powder and fry for 30 seconds, to release the aroma
Add the lentils, spinach, stock, and crushed tomatoes. Bring to a boil, then lower heat to a gentle simmer and cook for 15 to 20 minutes, or until the lentils are tender but not falling apart.
Meanwhile, in a large skillet, heat the remaining tablespoon of oil over medium-high heat. Add the eggplant and cherry tomatoes, season with ½ teaspoon of salt and fry until the eggplant is soft and golden brown and the tomatoes blister, about 10 minutes.
When the lentils are ready, add the eggplant mixture, coconut milk and the remaining teaspoon of salt, or to taste, to the lentils. Heat for a minute, then serve with your choice of garnishes.