Preheat the oven to 200°C, fan 180°C, gas 6. Break the cauliflower into small florets and toss with any good leaves onto a large baking pan, retaining the stem.
Toss with ½ tbsp olive oil, a pinch of sea salt and black pepper, and a splash of water until evenly coated. Roast until golden and gnarly, about 25-30 minutes.
In the meantime, coarsely grate the stalk and set it aside. 2 clementine's, peeled and sliced; carefully chop the mint leaves, leaving the baby ones for later; pestle and crush the nuts
Place the couscous in a heatproof bowl, season with salt and pepper, and cover with boiling kettle water. Set aside for 5 minutes.
Squeeze the juice of the remaining clementine's into a small bowl with ½ tbsp red wine vinegar and 1 tbsp extra virgin olive oil, then season.
Season the tahini, yogurt, and 1 tbsp red wine vinegar in a small bowl to produce the creamy dressing.
Fold in the grated cauliflower stalk, chopped mint, and clementine dressing after fluffing the couscous.
Place on a large serving plate to serve. Drizzle the tahini dressing and harissa over the clementine slices, then arrange the cauliflower in the center of the dish, finishing with the nuts and reserved tiny mint leaves. Served hot or cold, this dish is delicious.