Sweet potato falafels with coleslaw

INGREDIENTS

• 1 large or 2 small sweet potatoes , about 700g/1lb 9oz in total
• 1 tsp ground cumin
• 2 garlic cloves , chopped
• 2 tsp ground coriander
• handful coriander leaves , chopped
• juice ½ lemon
• 100g plain or gram flour
• 1 tbsp olive oil
• 4 wholemeal pitta breads
• 4 tbsp reduced-fat houmous
• 2 tbsp red wine vinegar
• 1 tbsp golden caster sugar
• 1 small onion , finely sliced
• 1 medium carrot , grated
• ¼ each white and red cabbage , shredded