The day before you want to make the soup, rinse the dried white kidney beans and place in a large bowl. Cover with cool water, making sure there is at least 2 inches of water above the beans. Let rest at room temperature overnight.
Drain the rehydrated beans and rinse with cool water. Place in a large heavy-bottomed pot or Dutch oven. Cover again with cool water, making sure there is at least 2 inches of water above the beans.
Bring to a boil over high heat. Once boiling, cover with a lid, reduce the heat to medium-low and simmer for 1 hour, or until the beans are tender. They should fall apart when pressed between your fingers. Drain the beans in a colander, then set aside. Do not rinse.
Return the pot to the stove and heat over high heat. Once hot, add the olive oil and onion. Sauté for 4 to 5 minutes or until the onion is softened and translucent. Season with the salt and pepper, then add the garlic, rosemary, and bay leaf. Cook for 30 seconds.
Add the drained beans back to the pot and add the chicken stock and Parmigiano Reggiano cheese rind. Mix to combine. Reduce the heat to medium, partially cover the pot with the lid leaving a 1-cm gap. Cook for 30 minutes.
Once cooked, remove the bay leaf, rosemary sprigs, and the Parmigiano Reggiano cheese rind from the pot. Use an immersion blender to puree roughly half of the soup so that you are left with a few whole beans and a creamy bean soup base.
To serve, ladle the soup into bowls and garnish with some grated Parmigiano Reggiano cheese, a drizzle of extra virgin olive oil, and a sprinkling of parsley. Serve warm with a side of toasted baguette and enjoy!