Place the haricot beans into a large container and cover with several inches of cool water; let stand 8 hours or overnight. Drain and rinse before using.
Cook the soaked beans in a pressure cooker in 1 litre of water for 25 minutes. Use the natural release method to release pressure. Do not drain.
Bring a separate pot of salted water to the boil. Add the kale and simmer until kale is bright green and tender, about 2 minutes. Drain in a colander and cool under cold running water. Set aside.
Heat olive oil over medium heat in the soup pot. Brown the chorizo, about 5 minutes. Remove from the pot with a slotted spoon and set aside. Add shallots to pot and cook until soft, about 3 minutes. Pour in a splash of chicken stock and scrape up any browned bits of chorizo.
Return the chorizo to the pot along with the beans and their cooking liquid. Stir in the chicken stock. Bring soup to the boil, reduce heat to low and simmer uncovered for 15 minutes. Add the kale and cook about 4 minutes longer. Season with salt, pepper and hot sauce to taste.