In a lightly greased nonstick skillet, cook leeks and onion for 5 minutes or until tender and just beginning to brown; set aside., In a large saucepan, cook flour and garlic powder in oil for about 2 minutes or until lightly browned. Gradually whisk in broth. Stir in the bay leaves, salt, pepper, pepper sauce, Worcestershire sauce and nutmeg. Bring to a boil; cook for 1-2 minutes or until thickened. , Stir in potatoes and leek mixture; return to a boil. Reduce heat; cover and simmer for 15-20 minutes or until potatoes are tender. Stir in milk and evaporated milk; heat through. Discard bay leaves.