In a food processor, combine fresh parsley, cilantro, and three cloves of garlic. Pulse until finely chopped, then add two tablespoons of red wine vinegar, half a teaspoon of dried oregano, and a pinch of red pepper flakes, salt, and pepper. While the processor is running, slowly drizzle in half a cup of extra virgin olive oil until the mixture is well-blended and vibrant. Set the chimichurri aside to allow the flavors to meld.

Pat the sirloin steak dry with paper towels and season it generously with salt and pepper. Heat one tablespoon of olive oil in a large skillet over medium-high heat until shimmering. Sear the steak for about 3-5 minutes per side, or until it reaches a medium-rare internal temperature of 130-135°F. Once cooked, remove it from the skillet and let it rest for a few minutes before slicing against the grain for maximum tenderness.

In a large mixing bowl, combine six cups of mixed salad greens, one cup of halved cherry tomatoes, and half a medium cucumber, sliced. Add a quarter of a small red onion, thinly sliced, along with one diced avocado, half a cup of cooked corn, and half a cup of black beans. Toss everything gently to combine, ensuring that the vibrant ingredients are evenly distributed for a beautiful and colorful presentation.

Divide the salad mixture among four bowls, creating a generous base for each serving. Top with slices of the rested steak, drizzling the prepared chimichurri sauce generously over the top. Serve the Chimichurri Steak Salad Bowl immediately while fresh.