½ tsp ground coriander
1 small bunch fresh coriander, leaves reserved, stalks finely chopped
1 garlic clove, crushed
1 tsp black onion seeds
300²µ/10½´Ç³ú parsnips, grated
300²µ/10½´Ç³ú sweet potatoes, grated
pinch dried chilli flakes
1–2 tbsp plain flour
½ tsp ground cumin
harissa paste, to taste
4 tbsp olive oil
1 medium free-range egg, beaten
150g/5½oz Greek-style yoghurt