Cut the broccoli head into small 1-inch florets, ensuring they're roughly uniform in size for even dressing absorption. Slice the tomatoes into halves or quarters depending on their size—you want pieces similar in scale to the broccoli florets. Thinly slice the red onion, separating the layers slightly so they soften nicely as they marinate.

Combine the prepared broccoli, tomatoes, and red onion in a large bowl. Pour the red wine vinaigrette over the vegetables and toss everything together until well coated. I find that cutting the broccoli into smaller, uniform pieces really helps the dressing penetrate better, creating more flavorful bites throughout. Cover the bowl and let it sit at room temperature for at least 15 minutes, which allows the vegetables to soften slightly and the flavors to meld together beautifully.

Just before serving, sprinkle the crumbled feta cheese over the top of the salad and toss gently to distribute it throughout. The feta adds a creamy, tangy contrast to the bright vinaigrette, and adding it at the end keeps it from getting too soft or absorbed into the dressing.