How to Make It
In a large enameled cast-iron casserole, heat 1 tablespoon of the olive oil until shimmering. Blot the flank steak dry with paper towels and season it generously with salt and pepper. Working in 2 batches, brown the meat over high heat, about 10 minutes. Transfer the browned steak to a plate and repeat with the remaining meat. Return all of the meat to the casserole. Add the water and 1 bay leaf; bring to a boil. Reduce the heat to low, cover and simmer until the meat is very tender, 1 1/2 to 2 hours.
Transfer the stewed meat to a large bowl and cover with aluminum foil; reserve 3 cups of the cooking liquid. Discard the bay leaf.
In the same casserole, heat the remaining 1/4 cup of olive oil. Add the onions and red and green bell peppers to the casserole and cook over high heat, stirring frequently, until the onions are softened and golden, about 10 minutes. Add the garlic and cook, stirring, until fragrant, about 2 minutes.
Lay the cloves, cinnamon and the remaining bay leaf on a square of cheesecloth. Gather the edges and tie them with kitchen string; add the spice bag to the casserole. Stir in the tomatoes, capers and the reserved 3 cups of cooking liquid; bring to a boil, then simmer over moderately low heat until the sauce thickens, 15 minutes. Season with salt and pepper. Discard the spice bag.
Meanwhile, using 2 forks, pull the meat into long shreds. Add the meat to the sauce and simmer over low heat until warmed through, then serve.
Steamed white rice and black or pinto beans.