Heat 1 tbs oil in a medium saucepan. Add onion, garlic and cumin and cook for 5 minutes or until onion has softened. Add water, tomatoes with juice and lentils to pan. Bring to the boil, then reduce heat and simmer for 20 minutes or until lentils are tender.
Meanwhile, to draw out bitter liquid from the eggplant, toss eggplant with 1 tsp salt and place into a colander over a bowl for 10 minutes to drain. Rinse and pat dry with paper towel.
Combine garam masala, coriander, chili flakes and turmeric. Add eggplant and toss to coat. Heat remaining vegetable oil in a wok or deep frying pan over medium-high heat. If using parsley, fry the leaves for 2-3 seconds until crisp. Remove with a slotted spoon and drain on paper towel.
Add seasoned eggplant, in batches and cook, stirring for 1-2 minutes or until eggplant is golden. Drain on paper towel. Season soup salt and pepper to taste.
Serve soup into warm bowls, topped with eggplant. Garnish with fried parsley, if desired.