Remove the cheese rind, scraping off as much of the other soup ingredients as possible. Trim away the hard outer edge and then cut into 1/4 inch cubes.
Blend until smooth with an immersion blender, or carefully transfer to a standing blender.
Return the soup to the cooking vessel if using a standing blender, then add the cheese cubes and simmer for 10 minutes. Add the beans and simmer for 10 more minutes. Season to taste with additional salt (it may not need it) and a splash or two of sherry vinegar.
Serve drizzled with olive oil and sprinkled with red pepper flakes.
Notes
If you don't have any parmesan rinds stashed in your freezer, or a piece of cheese it can be trimmed away from, some cheese counters sell rinds for a reasonable price.
Recipe by A Modest Feast at http://www.amodestfeast.com/2016/01/30/broccoli-white-bean-soup/