In a bowl, combine the olive oil, minced garlic, rosemary, coriander, smoked paprika, lemon juice, salt, and pepper. Mix well and add the flank steak, ensuring it’s fully coated. Cover and marinate in the refrigerator for at least 20 minutes, or up to 2 hours for deeper flavor.
Cook farro according to package directions until tender. Drain and set aside once done.
Heat a skillet over high heat. Once hot, remove the steak from the marinade and sear for about 4-6 minutes per side, depending on the desired doneness. Let the steak rest for 5 minutes before slicing.
In a large mixing bowl, toss the cooked farro, diced cucumber, halved cherry tomatoes, sliced red onion, and kalamata olives together until evenly mixed.
In a small bowl, whisk together the Greek yogurt, olive oil, and lemon juice until smooth. Season with a pinch of salt if desired.
To assemble, divide the farro salad among bowls, top with sliced steak, crumbled feta, and avocado if using. Drizzle with the yogurt dressing over the top and garnish with fresh parsley.