Adapted from the New York Times Cabbage, Potato and Leek Soup, my version packs more protein with the addition of white tepary beans. I also add a chile kick and a squeeze of lemon to counter the buttery base.
If making in advance, cool completely in an ice water bath after step 3 before storing, covered, in the fridge. When ready to serve, gently reheat in a stockpot over medium heat until bubbly hot. Continue with step 4.