- Preheat oven to 180°C. Line a baking tray with parchment paper.
- Slice the cauliflower into finger-thick pieces.
- Place on tray, drizzle with olive oil and vinegar, then top with walnut pesto.
- Bake for 15-20 minutes, until cauliflower is soft.
- Remove from oven and transfer to a serving dish. Top with capers and sprinkle with black pepper.