In a large bowl, combine the trimmed and cut sirloin steak pieces with 3 tbsp olive oil, 2 tbsp lemon juice, red wine vinegar, minced garlic, dried oregano, 1/2 tsp salt, and 1/4 tsp black pepper. Toss well to ensure all steak pieces are coated. Let the steak marinate at room temperature for at least 15 minutes, or cover and refrigerate for up to 2 hours for deeper flavor.

While the steak marinates, prepare the couscous. In a small saucepan, bring the vegetable broth (or water) and 1/4 tsp salt to a boil. Remove the pan from heat, stir in the instant couscous, cover with a lid, and let it stand for 5 minutes. After 5 minutes, fluff the couscous with a fork.

In a small bowl or jar, whisk together the extra virgin olive oil, 2 tbsp lemon juice, chopped fresh dill, garlic powder, 1/4 tsp salt, and a pinch of black pepper until well combined. Set aside.

Heat a large skillet or grill pan over medium-high heat. Once hot, add the marinated steak pieces in a single layer. Do not overcrowd the pan; cook in batches if necessary. Cook for 2-3 minutes per side for medium-rare, or longer for desired doneness. Remove the cooked steak from the pan and let it rest on a cutting board for a few minutes.

To assemble the bowls, divide the fluffy couscous among four serving bowls. Top each with the cooked steak, halved cherry tomatoes, diced cucumber, thinly sliced red onion, halved Kalamata olives, and crumbled feta cheese.

Drizzle each bowl generously with the lemon-herb dressing. Garnish with fresh chopped parsley and mint. Serve immediately and enjoy your Mediterranean Steak Bowl!