Prep the Cauliflower: Remove the green stalks from the cauliflower and set aside.
Par-Boil the Cauliflower: Bring a medium pot of salted water to a boil, then reduce to a gentle simmer. Cut the beetroot into small bite-sized pieces and add it to the pot with all the juice from the pack. Add the cauliflower head whole and boil for 10 minutes.
Apply the Harissa: After boiling, remove the cauliflower. (Discard the beetroot or save it for later.) Drain the cauliflower and dry it as thoroughly as possible. While still warm, spread the harissa or spicy red pepper pesto evenly over the top and sides of the cauliflower.
Roast the Cauliflower: Preheat your air fryer or oven to 200°C. Place the harissa-covered cauliflower on a baking tray. Lightly spray with oil and sprinkle with a pinch of salt. Roast for 20 minutes or until the cauliflower becomes nicely charred and crispy.
Prepare the Tahini Cream: While the cauliflower is roasting, prepare the tahini cream. In a bowl, combine the tahini, soy yoghurt, lemon juice, and a pinch of salt. Mix until smooth and creamy.
Prepare the Salsa Verde: For the salsa verde, finely chop the parsley, mint, capers, and garlic, leaving a little texture. Transfer to another bowl and whisk together with the mustard, lemon juice, olive oil, and salt. Adjust seasoning to taste.
Serve: Slice the roasted cauliflower into 4 quarters. To serve, place each cauliflower steak on a bed of tahini cream and drizzle the salsa verde over the top in a zigzag pattern for a beautiful colour contrast. Enjoy your perfect plant-based roast!