Best-Ever Potato and Leek Soup

Yes, I know, this is a big batch of soup, but like many of my soup recipes, I make it once and freeze it in quart containers. Potato and leek soup was what French chef Louis Diat cooked one cold summer morning at the Ritz in New York City, more than a century ago. The soup was left in the fridge all day, then spun, strained, creamed and turned into chilled vichyssoise, the classic French soup. I love that elegant soup, but in recent years I have taken to eating it the "original" way: hot, and during autumn, when it warms my bones and makes for one of my favorite lunches along with salad and crusty bread.