Make the dressing: Whisk together all of the ingredients except the olive oil (1 lemon, 1/4 cup red wine vinegar, 1 tablespoon sugar, 1 teaspoon salt, and 1 tablespoon fresh oregano). Pour the 2/3 cup extra virgin olive oil in a slow, steady stream while whisking constantly. Continue to whisk once all the olive oil has been added until the dressing has emulsified.
Cook the pasta: Heat a large pot of water with 1 tablespoon kosher salt over high heat. Once it comes to a boil, add the 16 ounces pasta and cook al dente. You want it to be tender but still have a bit of a bite to it. Prior to draining the pasta, reserve a cup of the salted pasta water. This can be added to the mixed salad just before serving if it seems too dry. Drain the pasta and immediately return it to the pot. While it is still hot, add about half of the prepared dressing and toss to coat. This will allow the flavor of the dressing to absorb into the pasta, will leaving the remaining dressing for the finished pasta salad.
Combine salad ingredients: Once the pasta has completely cooled, add the remaining salad ingredients (1 medium red onion, 6 ounces kalamata olives, 1 red bell pepper, 2 cups cherry or grape tomatoes, 1 cucumber, and 1 cup feta cheese and toss to combine. Chill at least 2 hours, if possible.
Add remaining dressing: Just prior to serving, add the remaining salad dressing and toss to combine. The dressing is added at the end to prevent it from absorbing into the pasta. If the pasta salad seems dry, add small amounts of the reserved pasta water until it looks and tastes how you want it.
Notes
serving size based on an estimated 1/2 cup of cooked pasta per person, or about 3/4 cup pasta salad, per person.