Begin by boiling a large pot of salted water over high heat. Once boiling, add the rotini pasta and cook according to the package instructions, usually around 8-10 minutes, until it's al dente. Drain the pasta in a colander and rinse briefly under cold water to stop the cooking process. Set aside to cool completely.

While the pasta cools, prepare your fresh vegetables. Dice the cucumber, carrots, sweet onion, bell pepper, and kalamata olives into small, even pieces to ensure uniform flavor. Finely chop the fresh parsley as well.

In a large mixing bowl, combine the cooled rotini pasta with the chopped cucumber, carrots, onion, olives, bell pepper, and parsley. Toss everything gently but thoroughly using a large spoon or spatula.

In a mason jar or a medium bowl, combine the plain unsweetened Greek yogurt, red wine vinegar, lemon juice, minced garlic, onion powder, dried oregano, and fresh dill. Shake the jar or whisk the mixture until everything is well combined.

Pour the creamy tzatziki dressing over the pasta and vegetable mixture. Gently toss the salad until every morsel is coated in the delicious dressing.

Once combined, transfer the Tzatziki Pasta Salad into an airtight container or cover the bowl with plastic wrap. Refrigerate for at least one hour to let the flavors meld together.

After chilling, give the pasta salad a quick toss and taste for seasoning. Adjust with additional salt, pepper, or a splash more lemon juice, if desired. Serve cold.