Top tuna with cheese, packing it on generously, and slide sandwiches under broiler. Broil until cheese melts and bubbles, 4-5 minutes. Remove tuna melts from broiler and serve immediately.

I ordered a tuna sandwich from Subway, Jimmy John's, and Jersey Mike's to see which big-name chain makes the best classic sub. One stood out.

Sandwiches containing fish come in many different shapes and forms, from the humble tuna with mayo to the timeless ... and ...

Stir in the tuna, onion, olives and capers. Divide the tuna mixture between 4 bread slices. Top with the lettuce and remaining bread slices. Tip: This recipe can be halved to make 2 servings.

Attention tuna ... block of tuna. Or, if you live near an ocean, you can buy fresh tuna. Pro Tip: Make sure you have the market give you a bag of crushed ice to go with the fresh fish.

Subway's tuna salad sandwich ... tuna DNA" in samples of the sandwich. Source: Insider Subway contends that the test doesn't prove anything, because cooking the fish can make the tuna DNA ...

Jimmy John's sandwich had a great balance of ingredients and spot-on taste and texture. I think ordering a tuna sub is always going to be a bit of a risk. Will the fish taste fresh enough?