In a large enameled cast-iron casserole, heat the olive oil until shimmering. Add the bacon and cook over moderate heat, stirring, until crisp, about 8 minutes. Using a slotted spoon, transfer the bacon to a plate. Add the onion and garlic to the casserole and cook, stirring, until softened, about 8 minutes. Add the green beans and crushed red pepper and cook, tossing, until the beans are coated with fat and just beginning to soften, about 3 minutes. Add the tomatoes, chicken stock, bay leaves and crisp bacon, season with salt and bring to a boil. Reduce the heat to moderately low, cover partially and cook, stirring occasionally, until the beans are tender, about 20 minutes.