How to Make It
Heat 1/3 cup of the olive oil in a soup pot. Add the onion, garlic and a large pinch of salt and cook over low heat, stirring occasionally, until the onion is softened, about 5 minutes. Stir in the cumin and cook until fragrant, about 1 minute. Add the tomatoes and bring to a boil. Cook over moderate heat, stirring occasionally, until the tomatoes are soupy, about 20 minutes.
Pass the soup through a food mill or fine sieve, pressing hard on the solids. Return the soup to the pot. Add the chicken stock and sugar and season with salt and pepper. Simmer over moderate heat until reduced to 10 cups, about 25 minutes. Stir in the parsley and chopped lovage. Ladle the soup into shallow bowls, garnish with the lovage leaves and drizzle with olive oil. Serve hot.