In a mixing bowl, combine olive oil, minced garlic, lemon juice, oregano, and thyme. Whisk in salt and black pepper to taste. Place the sirloin steak into a shallow dish, pour the marinade over it, ensuring it's well-coated. Let it marinate for 30 minutes or refrigerate for up to 4 hours.

In a bowl, mix Greek yogurt, grated cucumber, minced garlic, and lemon juice. Add chopped fresh dill and stir until well combined. Cover and chill in the refrigerator.

In a small bowl, whisk together olive oil, lemon juice, honey, and minced garlic. Add oregano, salt, and pepper to taste.

Heat a cast-iron skillet over medium-high heat. Remove the steak from the marinade and place it in the skillet. Sear each side for 4-5 minutes for medium-rare. Let it rest for 5 minutes before slicing.

Start with a layer of cooked grains, then add the grilled steak slices. Top with roasted chickpeas, cherry tomatoes, cucumber, red onion, and feta cheese.

Drizzle tzatziki sauce and lemon vinaigrette over the bowl, then sprinkle with fresh herbs.