01 -
Take a heavy-based saucepan and put it over medium heat. When the pan is slightly hot, add olive oil into it and then put in the chopped onion. Cook until tender and translucent, about 3-4 minutes. Add the chopped leeks and continue cooking for a few more minutes until the leeks have softened.
02 -
Once the leeks are nice and tender, take the pan off the heat and add the flour to it. Stir constantly as you incorporate the flour so that it doesn't stick to the base of the pan and forms a smooth mixture with the vegetables. This will help thicken your soup.
03 -
Return the pan to the stove over medium heat. Gradually add the chicken broth while continuously stirring to prevent lumps from forming. Bring the mixture to a gentle boil, then add the cubed potatoes. Reduce heat to a simmer and cook for 15-20 minutes, or until the potatoes are fork-tender.
04 -
Once the vegetables are soft, remove the pot from heat. Using a hand blender, carefully blend the soup directly in the pot until smooth and creamy. If you don't have a hand blender, transfer the soup in batches to a regular blender, being careful with the hot liquid.
05 -
Return the blended soup to low heat and stir in the milk. Heat gently but do not allow the soup to boil after adding the milk, as this can cause it to separate. Taste and adjust seasonings if needed, adding salt and pepper to your preference.
06 -
Ladle the hot soup into bowls. Garnish with freshly chopped parsley or other herbs of your choice. Serve immediately with your favorite bread, breadsticks, or garlic toast for a complete meal.