Recipe Tips You can go one-step further and add cheese to this dish, making it a classic tuna melt sandwich. Share your version of this recipe Do you have a different method of making a tuna fish sandwich? We cannot be more excited to learn about your version of this dish. Don’t forget to share your recipe with us. Frequently Asked Questions Why do we need to rinse the water from the tuna can? The tuna fish water contains excess sodium. Rinsing it helps you avoid that excess sodium in your dish. What can I use instead of mayonnaise to make tuna fish sandwich? You can use avocado, hummus or Greek yogurt instead of mayonnaise to make a tuna fish sandwich.