- Frozen yellowfin tuna fillets - Good source of protein - Good source of Omega-3 - Simply thaw and cook Delicious in a variety of meals, I&J Tuna Portions are also a good source of Omega-3 fatty acids. Try sprinkled with lemon zest for an extra kick. Easy to prepare and delicious to eat, I&J Tuna Portions are a true family favourite. Enjoy them on their own seasoned with ginger cilantro marinade or serve with a side of roasted lemon potatoes for a delicious lunch or dinner. I&J Tuna Portions are yellowfin tuna fillets that are easy to prepare in a number of ways. Try cooking them in a little olive oil and season with salt and lemon to complement the delicate flavour of the meat. The I&J tuna portions are also a good source of Omega-3 and a good source of protein.