Bring a large pot of salted water to a rolling boil over high heat. Add 1 cup of orzo pasta and cook for about 10 minutes, or until al dente. Once cooked, drain the orzo in a colander and rinse it under cold water to stop the cooking process.

In a spacious mixing bowl, combine the cooled orzo with 4 cups of baby spinach, 1 diced red bell pepper, 1 diced cucumber, ¼ cup of finely chopped red onion, and ½ cup of sliced Castelvetrano olives, along with ½ cup of Kalamata olives.

In a separate bowl, prepare the vinaigrette by whisking together ¼ cup of canola oil, ¼ cup of olive oil, 3 tablespoons of freshly squeezed lemon juice, 1 teaspoon of dried oregano, and a pinch of kosher salt and black pepper to taste.

Pour the freshly made vinaigrette over the salad mixture, ensuring that all the ingredients are lightly coated. Use a spatula to gently fold the salad, taking care not to break the feta cheese or vegetables.

Cover the salad with plastic wrap or a lid and refrigerate for at least one hour. For best results, let the salad chill overnight. When ready to serve, give it a gentle toss and sprinkle the remaining feta cheese on top.