In a mixing bowl, combine olive oil, minced garlic, lemon juice, dried oregano, thyme, salt, and pepper, then coat the sirloin steak. Marinate for at least 30 minutes.

Prepare tzatziki by mixing Greek yogurt with grated cucumber, lemon juice, minced garlic, chopped dill, salt, and pepper. Refrigerate for at least 15 minutes.

Whisk together olive oil, lemon juice, minced garlic, oregano, salt, and pepper to make the vinaigrette.

Heat a skillet over medium-high heat. Sear marinated steak for 4-5 minutes on each side for medium-rare. Rest before slicing.

Assemble the bowl: start with cooked grains, layer with steak, cherry tomatoes, cucumber, red onion, olives, feta, and herbs.

Top with tzatziki sauce and vinaigrette before serving.