How to Make It
In a large enameled cast-iron casserole or Dutch oven, heat the olive oil. Add the slab bacon and cook over moderately high heat, turning once or twice, until browned and crisp, about 8 minutes. Transfer to a plate.
Reduce the heat to low. Add the onion, garlic and chiles to the casserole and cook until just softened, about 5 minutes. Add the bacon, beans, serrano ham, thyme sprigs and bay leaf. Pour in the water and bring to a boil. Cover and simmer over low heat, stirring occasionally, until the beans are nearly tender, about 1 hour and 15 minutes.
Add the sausage to the casserole and cook, uncovered, until the beans are tender and the broth is slightly thickened, about 30 minutes. Discard the chiles, thyme sprigs and bay leaf. Ladle the feijoada into shallow bowls and serve with rice.