How to Make It
Season the pork with salt and pepper. In a large, shallow baking dish, mix 1 tablespoon of the olive oil with the parsley and pimentón. Add the tenderloins and turn to coat. Let stand at room temperature for 20 minutes or refrigerate for at least 1 hour or for up to 2 hours.
In a large, deep skillet, heat the remaining 1 tablespoon of olive oil. Add the pork and cook over moderate heat until browned, about 3 minutes per side. Transfer the pork to a plate.
Add the bay leaves, green bell pepper and onion to the skillet and cook over moderate heat until softened, 4 minutes. Add the flour and stir until a smooth paste forms. Gradually whisk in the wine; bring to a simmer, whisking for 2 minutes. Whisk in the stock and tomato paste and return to a simmer.
Return the pork tenderloin and any accumulated juices to the skillet and simmer over low heat for 10 minutes. Turn and simmer for about 10 minutes longer, or just until the pork is pink in the center. Transfer the pork to a cutting board and let stand for 5 minutes.
Meanwhile, remove the bay leaves from the pan sauce and pour into a food processor or blender and puree. Return the sauce to the skillet, add the piquillo peppers and bring to a simmer over moderately low heat. Season with salt and pepper. Thickly slice the pork and serve with the pan sauce.