New Royal Fillets of Mackerel in Olive Oil with Lemon! Gourmet quality skinless and boneless North Atlantic mackerel in pure olive oil infused with bright, clean, fresh lemon flavor. A classic seafood combination. Extraordinary, light taste and moist texture â truly unique. Sustainably wild-caught, gluten-free, kosher-certified, hand-packed. The perfect tuna substitute. Try in sandwiches, on top of a salad, or right out of the can on a cracker!