In a lightly greased skillet, cook the leeks and onion for five minutes or until they're tender and just beginning to brown. Set aside.
In a large saucepan, cook the flour and garlic powder in oil until lightly browned, about two minutes. Gradually whisk the broth into your roux.
Stir in the bay leaves, salt, pepper, hot sauce, Worcestershire sauce and nutmeg. Bring to a boil and cook, stirring, for one to two minutes or until thickened.
Stir the potatoes and the leek mixture into the soup and return to a boil. Reduce heat, cover and simmer for 15 to 20 minutes or until the potatoes are tender. Stir in the milk and evaporated milk, and heat through. Fish out the bay leaves and discard them before serving.
