Spiced roast cauliflower with barley couscous

Ingredients

• 1 medium cauliflower, outer leaves and thick stem removed, cut into florets
• 2 red peppers, deseeded and cut into strips
• 1 red onion, cut into thin wedges
• 3 tbsp olive oil
• ½ tbsp ground cumin,
• ½ tbsp ground coriander
• 1 tsp chilli flakes – preferably aleppo
• 200g barley couscous
• Finely grated zest 1 lemon
• 250ml vegetable stock, hot
• 150ml boiling water
• Juice 1 lemon
• 1 tbsp tahini
• 1 garlic clove, crushed
• 50g flaked almonds, lightly toasted in a dry frying pan
• 50g sultanas
• Large handful fresh mint, chopped
• Small handful fresh coriander, chopped
• Small handful fresh parsley, chopped
• Yogurt and chilli flakes (optional) to serve