This aubergine soup light, fresh and a little bit sour. Don't use the eggplant peel, because very hard to make it mashed. Peel the eggplant and cut into small cubes, chop the onion and garlic too. Heat the oil in a large kettle and cook the eggplant, onion, and garlic in it, salt and pepper while stirring occasionally, until they are tender and golden browned. Add stock (or water) simmer the soup for about 15 minutes. Blend the soup in batches in a food processor or use immersive blender, transferring it as you blend it back to the kettle. Add the heavy cream, lemon juice and more season as you like. Let the soup boil once you have added the cream, but do not cook for minutes. Garnish the soup with balsamic vinegar and serve with grissini or toast. If you are not using it right away, store it in the refrigerator once it has cooled and heat up it without letting it boil.