Begin by cooking your gluten-free pasta according to the package instructions. Once it's fully cooked, rinse it with cold water to cool it down and prevent it from sticking together. Set the pasta aside and start preparing your vegetables. Dice the cucumber, bell pepper, roasted red pepper, red onion, and sundried tomatoes and add them to a large bowl. Next, chop the romaine lettuce and add it to the bowl as well.
Once all of your vegetables are prepared, it's time to add the pasta. Add the fully cooked gluten-free pasta to the bowl with the vegetables and mix everything together.
Now it's time to add the tzatziki sauce. Spoon 1/3 cup of hot pepper and garlic tzatziki over the salad and mix everything together until the pasta and vegetables are coated with the sauce.
Finally, crumble 3 tablespoons of fat-free feta cheese over the top of the salad and give everything a final stir. Your Greek pasta salad is now ready to serve!