jamon: cut into 0.6cm strips padrón stemmed, seeded, and torn into 1.2 cm-wide strips onine: finely chopped piquillo peppers: drained and torn into 1.2 cm-wide strips tomatoes: cored, peeled, and roughly chopped tuna: cut into eight 113g steaks
In a large saucepan, warm 2 tablespoons duck fat over medium heat. Add the jambon and garlic, and cook, stirring, until lightly browned, about 6 minutes. Add the padrón peppers and onions to the pan and cook, stirring, until softened and lightly browned, about 14 minutes. Stir in the tomato paste, cook for 2 minutes, then add the piquillo peppers along with the tomatoes, parsley, thyme, and bay leaf. Season the peppers with salt and piment d'Espelette and cook, stirring occasionally, until the tomatoes break down and the pipérade is thickened but still loose, about 10 minutes. Scrape the pipérade onto a serving platter and keep warm.
Meanwhile, warm the remaining 3 tablespoons duck fat in a large skillet over high heat. Season half the tuna steaks with salt, then add to the skillet and cook, turning once, until medium rare, 2 to 3 minutes. Transfer the tuna steaks to a plate and repeat cooking the remaining raw tuna steaks. Season all the tuna steaks with piment d'Espelette, then arrange the steaks over the pipérade and serve.