1. Rinse the tomatoes.
2. If they are not treated, do not peel them.
3. Cut them roughly into pieces, as well as the peeled onions.
4. Take a large non-stick pan.
5. In Quebec, we would sauté the onions and tomatoes in 1 tbsp of salted butter (half-salted), but in this case, I used olive oil.
6. Add the celery leaves (which I always have in the freezer...
7. What to do with the leftover celery leaves).
8. Let it cook for about ten minutes, stirring regularly.
9. Add 2 tbsp of corn flour and mix until the flour is dissolved.
10. Moisten with chicken broth, then add water to cover the vegetable mixture with water.
11. Slowly bring to a boil.
12. Cover and reduce the heat.
13. Simmer over low heat for 20 to 30 minutes.
14. Add the sugar cubes.
15. Season.
16. Blend.
17. Adjust the seasoning.
18. When serving, add the milk and garnish with chopped chives (which I also always have in the freezer).
19. My suggestions: - Replace the milk with heavy cream.
20. - If you find the soup too bitter, add an additional sugar cube!