Drain the artichokes and pat dry. Pour off the fat from the casserole and add the remaining 2 tablespoons of olive oil. Add the leeks and bay leaves and cook over low heat, stirring occasionally, until the leeks are softened, about 8 minutes. Add the garlic and pimentón and cook, stirring, until fragrant, about 2 minutes. Add the parsley, peppercorns and wine and simmer over moderately high heat for 5 minutes. Add the seared meat, stock, red pepper puree and the artichokes and bring to a simmer. Add a pinch of salt and cook over low heat, stirring occasionally, until the meat is tender, about 1 1/2 hours. Season with salt and pepper and serve.