Chop & wash leeks as shown above. Pat dry on paper towel.
Melt butter in medium soup pot. Stir in flour and cook over low heat until bubbling brown.
Slowly stir in chicken stock.
Add leeks, onion & potatoes and bring to a boil.
Simmer over medium/low heat for 20-25 minutes, until the potatoes are tender.
Blend the soup until smooth using an immersion blender.
Add Milk and seasonings to taste & heat through.
Serve in bowls topped with your favorite soup fixings.