Pat the steak dry with paper towels. In a shallow dish or zip-top bag, combine 3 tbsp olive oil, 2 tbsp lemon juice, minced garlic, 1 tsp dried oregano, 1/2 tsp salt, and 1/4 tsp black pepper. Add the steak, ensuring it's fully coated. Marinate in the refrigerator for at least 30 minutes, or up to 2 hours for best flavor.

While the steak marinates, combine rinsed quinoa, 2 cups water (or broth), and 1/4 tsp salt in a medium saucepan. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes, or until all liquid is absorbed and quinoa is fluffy. Remove from heat and let stand, covered, for 5 minutes. Fluff with a fork.

While quinoa cooks, prepare your vegetables: halve the cherry tomatoes, dice the cucumber, thinly slice the red onion, and halve the pitted Kalamata olives. Set aside in a large bowl.

In a small bowl, whisk together the dressing ingredients: 1/4 cup extra virgin olive oil, 2 tbsp lemon juice, 1 tbsp red wine vinegar, 1 tsp dried oregano, 1/2 tsp dried dill (if using), 1/2 tsp salt, and 1/4 tsp black pepper until well combined.

Remove the steak from the marinade and discard any excess marinade. Heat a grill pan or cast-iron skillet over medium-high heat until hot. Add the steak and sear for 4-6 minutes per side for medium-rare (internal temperature 130-135°F), or longer for desired doneness.

Transfer the cooked steak to a cutting board, tent loosely with foil, and let rest for 5-10 minutes before slicing against the grain into thin strips.

Divide the cooked quinoa among four serving bowls. Top each bowl with an even portion of the prepared vegetables (tomatoes, cucumber, red onion, olives) and sliced steak.

Drizzle generously with the lemon-herb dressing. Garnish with crumbled feta cheese and fresh chopped parsley. Serve immediately.