Cook the bacon. Heat a large stockpot over medium heat. Add the diced bacon and cook, stirring occasionally, until crisp and the fat has rendered, about 7–8 minutes. Use a slotted spoon to transfer the bacon to a paper towel–lined plate. Leave about 2 tablespoons bacon grease in the pan and discard the rest. (Or if you need more, just add in some oil.)

Sauté the veggies. Add the onion, carrots, and celery. Cook for 5 minutes, stirring occasionally, until the vegetables soften and the onion is translucent. Stir in the garlic and rosemary and cook for 1 minute, stirring frequently.

Simmer the soup. Add the stock, beans, bay leaf, and Parmesan rind. Bring to a simmer, then reduce heat to medium-low and cook uncovered for about 20 minutes, stirring occasionally.

Blend for creaminess. Remove and discard the bay leaf and Parmesan rind. Carefully transfer about 1 cup of the soup (including both beans and broth) to a blender, and blend until smooth. Return the blended mixture to the pot and stir to combine for a silky, lightly creamy texture. Repeat if you’d like a more pureed soup.

Season and finish. Stir the bacon back in (saving a handful for garnish, if you like). Taste and season generously with salt and pepper. Add a squeeze of lemon juice for brightness, if desired.

Serve. Ladle the soup into bowls and top with freshly grated Parmesan, extra crispy bacon, and a twist of black pepper. Enjoy!