1 tablespoon olive oil
1 white onion, roughly chopped
2 garlic cloves, minced
1–15 ounce can white beans (navy or cannellini beans)
1–28 ounce can diced tomatoes
2 cups vegetable stock
1 teaspoon kosher salt
1/2 teaspoon black pepper plus more for serving
1/4 teaspoon red pepper flakes
2 sprigs fresh rosemary
1 Parmesan rind (optional)
1 cup roughly chopped rapini or kale, stems removed
Shaved Parmesan and chopped parsley for serving
Heat the oil in a large saucepan over medium heat. Sauté the onion until it is soft and translucent, about 7-8 minutes. Add the garlic. After 30 seconds – 1 minute when the garlic becomes fragrant, stir in the beans, tomatoes, vegetable stock, salt, pepper, red pepper flakes, rosemary and the Parmesan rind, if using.
Increase the heat and bring the mixture to a boil. Then reduce the heat and allow the soup to simmer for 20 minutes until it has thickened. Add the rapini and simmer for 3-5 minutes letting it wilt. Discard the rosemary sprigs and Parmesan rind.
Divide the soup into bowls and top with shaved parmesan, parsley and a sprinkle of black pepper.