Bring a large pot of salted water to a boil. Add the rotini pasta and cook according to package directions until al dente. Drain well and rinse with cold water to stop cooking and cool down. Transfer to a large mixing bowl.

While the pasta cooks, dice the cucumber, halve the cherry tomatoes, thinly slice or finely dice the red onion, halve the pitted Kalamata olives, and chop the fresh parsley and mint. If using, dice the red bell pepper. Add all prepared vegetables and herbs to the mixing bowl with the cooled pasta.

Drain the halloumi cheese and pat it very dry with paper towels. Slice the halloumi into 1/2-inch thick pieces, then cut these into 1/2-inch cubes. Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the halloumi cubes in a single layer (cook in batches if necessary) and cook for 3-4 minutes per side, or until golden brown and crispy. Remove from skillet and set aside to cool slightly.

In a small bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper until well combined. Taste and adjust seasoning if needed.

Add the slightly cooled, pan-fried halloumi cubes to the mixing bowl with the pasta and vegetables. Pour the prepared lemon-herb vinaigrette over the salad.

Gently toss all ingredients together until everything is evenly coated with the dressing. For best flavor, cover and refrigerate the pasta salad for at least 30 minutes before serving, allowing the flavors to meld.