If using a head of cauliflower, first remove the florets, then place them in a food processor. Pulse until it reaches the size of grains of rice.
Transfer the cauliflower to a microwaveable bowl and add olive oil with a pinch of salt and pepper.
Microwave, loosely covered, for 2.5 minutes, and allow to cool while you prepare the rest of the salad.
Once the cauliflower rice is cooled, top with arugula, sliced tomatoes, diced green onions, crumbled feta cheese, pitted olives, and fresh parsley.
Whisk together olive oil, lemon juice, red wine vinegar, oregano, salt and pepper. Drizzle with vinaigrette, serve, and enjoy!