In a medium bowl, combine olive oil, minced garlic, lemon juice, dried oregano, thyme, salt, and pepper. Coat the sirloin steak generously with the marinade. Let it marinate for at least 30 minutes at room temperature or up to 4 hours in the refrigerator.

While the steak marinates, prepare the tzatziki sauce by mixing Greek yogurt, chopped dill, minced garlic, and salt. Cover and refrigerate until serving.

Whisk together olive oil, lemon juice, and honey (if using) in a small bowl to make vinaigrette. Season with salt and pepper to taste.

Heat a skillet over medium-high heat. Add the marinated steak and sear for 4-5 minutes on each side or until desired doneness. Let rest for 5 minutes before slicing thinly against the grain.

Cook chosen grains according to package instructions. If using pre-cooked grains, heat them through.

Assemble the bowl with grains as the base, topped with sliced steak, cherry tomatoes, cucumber, red onion, roasted chickpeas, olives, tzatziki, and vinaigrette.