Heat olive oil in a Dutch oven or large pot over medium heat. Add leeks and green garlic; cook and stir until tender, about 5 minutes. Add red potatoes, eggplants, and zucchini. Cook uncovered, stirring occasionally, until starting to soften, about 15 minutes.
Stir kale and lettuce into the Dutch oven until wilted. Pour in water and vegetable bouillon. Bring soup to a boil; simmer, covered, until flavors combine, about 1 hour.
Blend soup using a hand immersion blender until creamy.