In a bowl, whisk together the red wine vinegar, olive oil, Dijon mustard, dried oregano, salt, black pepper, lemon juice, and minced garlic until well combined. Place the cubed steak in a resealable bag or container and pour the marinade over it, ensuring all pieces are coated. Refrigerate for at least 2 hours, though up to 24 hours will develop deeper flavor. I find that marinating overnight really transforms the steak, making it more tender and flavorful throughout.
While the steak marinates, prepare the dressing by combining the plain yogurt, fresh dill, fresh mint, honey, lemon zest, and a pinch of salt in a bowl. Whisk until smooth and well blended, then refrigerate until ready to use. This dressing is best made a few hours ahead so the herbs have time to infuse.
While the steak finishes marinating, prepare all your bowl components: chop the romaine lettuce, dice the cucumber into 1/2-inch pieces, halve the cherry tomatoes, and ensure your rice is cooked and ready (warm or at room temperature). Measure out the kalamata olives, hummus, and feta cheese into small bowls for easy assembly. Having everything prepped and organized makes the final assembly quick and seamless.
Remove the steak from the refrigerator about 15-20 minutes before cooking to bring it closer to room temperature—this ensures even cooking. Heat a large skillet or cast iron pan over medium-high heat and add a light coating of oil. Once the pan is hot and shimmering, carefully add the steak cubes in a single layer, working in batches if needed to avoid crowding. Sear each side for 4-5 minutes, aiming for a medium-rare internal temperature of 130°F. Don't move the steak around too much—let it develop a nice golden crust before flipping.
Transfer the seared steak to a plate and loosely tent it with foil, letting it rest for 5-10 minutes. This allows the juices to redistribute, keeping the meat tender and juicy. While the steak rests, begin assembling your bowls by layering the chopped romaine lettuce in each bowl as the base, then arrange the cooked rice, cucumber, tomatoes, and olives around the bowl. Add a spoonful of hummus to each bowl and then top with the rested steak cubes and crumbled feta cheese.
Drizzle each bowl generously with the yogurt-herb dressing from Step 2, or serve it on the side if you prefer to control the amount. Give each bowl a final light drizzle of olive oil and a crack of fresh black pepper if desired. Serve immediately while the steak is still warm and the vegetables are crisp.