1
: In a large saucepan, heat oil over medium heat. Add onion, celery, carrot and garlic and cook, covered for 5 minutes, stirring occasionally. Add flour and cook, stirring for 2 minutes.
2
: Add stock, tomatoes, tomato paste, salt and pepper. Bring to a boil, stirring often. Reduce heat to simmer. Cover and cook for 10 minutes, stirring occasionally, until vegetables are tender. Gradually pour in warm evaporated milk. Purée soup with an immersion blender or in batches in food processor. Season to taste. Serve garnished with basil and Parmesan.