Add the tomato paste and stir well to dissolve. Pour in 1 quart (1 L) of chicken stock. Bring the soup to a gentle boil, then add the potatoes and kale. Reduce the heat to low and simmer, with the lid tilted, until the vegetables are cooked through, about 30 to 40 minutes. Add more chicken stock as needed or to your liking. Stir in the white beans and warm through.
About 10 minutes before serving, toast or grill the bread, or simply cut into slices. Drizzle with olive oil and rub with a cut clove of garlic while still warm. Season with a touch of salt and pepper. Ladle your soup into bowls and top with extra celery leaves and Parmesan cheese. Serve piping hot with your delicious bread for dunking.