Cook the sweet potatoes in a pan
of boiling water for 10-12 minutes
until tender. Meanwhile, put the
tomatoes, chickpeas, chilli flakes
and curry paste in another pan and
simmer gently for about 5 minutes.
Preheat the grill. Drain the sweet
potatoes and add to the tomato
mixture. Stir in the spinach and
cook for a minute until just starting
to wilt. Stir in the coriander, season
to taste and keep warm.
Sprinkle the chapatis with a little
water and grill for 20-30 seconds
each side. Spoon on the filling, top
with yogurt and fold in half to serve.