Preheat oven to 220° Place the cauliflower and broccoli on a baking tray lined with baking paper and drizzle with the oil. Top with the Dukkah and salt and toss to combine. Roast until golden brown, about 18 – 20 minutes.
To serve, arrange roasted vegetables on a platter. Top with slices of avocado, drizzle with the Romesco or pesto and scatter over toasted walnuts. Serve warm.