Peel onion and garlic. Peel and wash the carrot. Clean and wash the celery and put 1 stick aside. Chop the prepared vegetables roughly. Heat oil in a pot and steam the vegetables for about 3 minutes at medium heat.
Deglaze with stock and tomatoes and simmer covered for about 20 minutes. Meanwhile cook the pasta in plenty of boiling salted water for about 8 minutes. Drain, quench and let drain. Wash, quarter and seed the tomatoes.
Cut the fruit flesh into strips. Clean and wash spring onions. Cut spring onions and remaining celery stalk into thin, sharp slices. Strain tomato soup, put it into a pot and bring it to the boil.
Add sauce thickener and cook for 2 minutes. Add tomato, spring onions, celery and pasta and bring to the boil. Season with salt and pepper. Put soup into plates and garnish with basil as desired.