Preheat your oven to 400°F (200°C) and prepare your baking sheet by lining it with parchment paper.

Cut the cauliflower into bite-sized florets and toss with olive oil, salt, and pepper. Spread on the baking sheet and roast for 20-25 minutes.

Chop the remaining vegetables: dice the red onion, halve the cherry tomatoes, and prepare olives, capers, and herbs.

In a small bowl, whisk together lemon juice, olive oil, Dijon mustard, honey, salt, and pepper to make the dressing.

Transfer roasted cauliflower to a mixing bowl, combine with red onion, cherry tomatoes, olives, capers, parsley, and oregano.

Pour dressing over the salad and toss gently to combine. Serve warm or chilled.