Add the chorizo and onion and cook over high heat, stirring, until the onion is softened, about 3 minutes.
Add the garlic and parsley and cook, stirring, for 2 minutes.
Add the chicken stock, water, red and navy beans, bay leaves, thyme and crushed red pepper and bring to a boil.
Cook over moderate heat until the beans are tender, about 1 1/4 hours.
Add the potatoes and kale to the stockpot, season with salt and pepper and cook over moderate heat, stirring occasionally, until the potatoes are tender, about 30 minutes.
Remove the bay leaves.
Serve the soup in deep bowls with plenty of crusty bread.