Perfect as full meal on its own or as part of a more elaborate spread, this salad is best enjoyed at room temperature. If you’re using leftover rice from the fridge, allow it sit out for a bit before preparing the salad. Oftentimes, when rice sits in the fridge, it sticks together in a single mass. Some ways around it include adding more oil to the water when cooking and allowing the rice to cool completely on a large baking sheet before transferring to a container and into the fridge. Finally, even if it is clumping together, using two forks that you gently pull in opposite directions, you can easily fluff the rice apart.
The jarred style of tuna tends to be better quality than the canned, with bigger pieces and better texture. However, if you can’t find jarred tuna, canned tuna will still work. The flavors in the salad are quite strong, so if the jar/can of tuna you use is one or two ounces off, it will still work out fine.
As for the vegetables, they were chosen for their crunch as a nice contrast to the fluffy rice and tender tuna, but you can substitute with whatever you have on hand. After all, this is a dish meant to repurpose leftovers, not send you scavenging for something you don’t have.