Start by boiling your rotini or fusilli pasta until it is al dente. You will know it is ready when it has a slight bite and looks glossy. Rinsing the pasta under cold water helps stop the cooking and keeps it from clumping. Avoid overcooking, as it will turn mushy.
Add the drained tuna to a large mixing bowl. Let it spread out and break it into smaller chunks with a fork. This helps it meld well into the salad while avoiding over mixing, which can turn it into paste.
Toss in the diced red bell pepper, grated carrot, diced celery, and red onion. Enjoy the colorful mix and the fresh crunch. While the onion adds needed zing, do not overdo it or it may overpower the other flavors.
In another bowl, stir together the Greek yogurt, mayonnaise, sweet pickle relish, sriracha, apple cider vinegar, sea salt, and black pepper. This will yield a creamy, zesty dressing. If it seems too thick, a little splash of water will help, but be cautious not to make it too runny.
Gently fold the cooked pasta into the tuna and veggie mixture, pouring the dressing as you go. The salad should start to look creamy and inviting. Be careful to mix lightly to avoid breaking down the pasta.
Place the salad in the fridge for about one hour. This allows all the flavors to blend beautifully. After chilling, taste and adjust the seasoning, as chilling can sometimes mute the flavors.