Stir in the thyme, rice, stock, salt and pepper. Bring to a boil, partially cover and reduce heat. Simmer for 25 minutes.
Stir in butternut squash, cover slightly and simmer for an additional 25-30 minutes or until squash is tender. Add chopped greens and stir until wilted.
Taste for seasoning and garnish with fennel fronds, if desired. If you like a little acidity, add a few drops of apple cider vinegar. (I think the soup is better with the vinegar.)
Recipe by Pamela Salzman at https://pamelasalzman.com/rustic-butternut-squash-soup-with-fennel-and-wild-rice/