Heat the oil in a large pot over medium-high heat. Add the sausage and cook, stirring to crumble, until browned and fully cooked, about 7 minutes.

Transfer 1 cup of the beans to a bowl along with ½ cup of chicken broth. Use the back of a fork to press and mash until mostly smooth.

Add the remaining un-smashed beans to the pot, stirring to coat in sausage drippings, and cook for 1 minute. Add remaining chicken broth, stirring to release any bits stuck to the bottom of the pot, and bring to a boil over medium-high heat. Stir in the mashed bean mixture, reduce the heat, and simmer until flavorful, 5 to 7 minutes.

Use a spoon to remove any excess fat from the top, if desired, and take the pot off the heat. Add the spinach and stir to combine. Once the spinach is just wilted, taste for seasoning, adding salt and pepper as needed. Portion into bowls, garnish, if desired, and serve.