In a mixing bowl, whisk together olive oil, minced garlic, lemon juice, dried oregano, thyme, salt, and black pepper. Coat the sirloin steak thoroughly in the marinade. Let it marinate at room temperature for 30 minutes or refrigerate for up to 4 hours.

In another bowl, combine Greek yogurt, grated cucumber, chopped fresh dill, minced garlic, and a pinch of salt. Stir until well incorporated and creamy. Cover and refrigerate for at least 15 minutes.

In a small bowl, whisk together lemon juice, olive oil, salt, and pepper. Adjust seasoning as desired.

Preheat a cast-iron skillet over medium-high heat. Add the marinated steak and sear for 4-5 minutes on each side until a perfect medium-rare to medium finish. Rest for 5 minutes.

Slice the steak thinly against the grain for tender bites.

Layer cooked grains in a bowl, top with sliced steak, halved cherry tomatoes, diced cucumber, sliced red onion, and Kalamata olives. Add tzatziki and a drizzle of vinaigrette.

Garnish with chopped fresh herbs like parsley or dill and serve immediately.