Chop the top portion off the garlic bulb to expose a bit of the cloves, leaving the paper in tact. Set bulb on a sheet of aluminum foil and drizzle 1 Tbsp olive oil onto it, letting the oil sink into the cloves. Wrap the bulb up in foil and bake for 30 minutes at 400 degrees F, or until cloves are soft and lightly browned.

In a large pot, heat 1 Tbsp olive oil over medium heat then add onion and celery. Cook until celery is bright green and onion is soft, about 5 minutes.

Add beans, broth, milk, pepper, and 1 Tbsp of the roasted garlic cloves. Cook over medium heat for 15 minutes.

Use a slotted spoon to remove and reserve 2 cups of the veggies. Working in batches, or with an immersion blender, blend the remaining soup until creamy. Add the 2 cups of veggies back into the soup.

Add spinach and cook a few minutes until wilted. Serve warm, optionally topped with parmesan and rosemary.