Get a large enough pan, and melt the butter into it.
2 tablespoons Butter
Add the leeks, celery, and carrots to the pan. Mix and cook the vegetables for 7-8 minutes.
1 cup Leek, 1 cup Celery, ½ Cups Carrot, 1 clove Garlic
Add the all-purpose flour to the pan. Mix well and continue to fry all the vegetables for another 2 minutes.
1 tablespoon All-purpose Flour
After the vegetables have smothered enough add the vegetable broth. Mix well.
2 ½ Cups Broth
Let the soup simmer until the vegetables are cooked through.
If you want a thicker soup, mix the 1/2 cup of sour cream with an egg.
½ Cup Sour Cream, 1 Egg
When the vegetables are cooked, use a hand blender to turn the soup into a cream.
Adjust the soup with salt and pepper to your taste.
Finally, add the sour cream or egg-cream mixture to the soup.
Mix all the ingredients well and the soup is ready to be served.
Optionally for cheese lovers: Pour the soup into a bowl suitable for the oven, add your favorite cheeses on top. In my case, I used mozzarella and pecorino.
¼ Cup Mozzarella, ⅕ Cup Pecorino Cheese
After that, preheat the oven to 350°F (180°C) and put the bowl in the oven until the cheese melts.
The soup is ready to be served on plates. Enjoy your meal! You can sprinkle a little bit of freshly chopped parsley.
Parsley
Quick Note
I highly recommend reading the entire recipe to find more tips and notes about this recipe. Read Full Recipe ⇑