A piquant and interesting soup making the most of cooking apples

45g butter
1 onion, chopped
1 tsp chopped fresh root ginger
1 heaped tsp Thai green curry paste
½ tsp ground cumin
500g parsnips, peeled and chopped
1 Bramley or 2 Granny Smith apples, peeled and chopped
1 litre beef stock
155ml plain yoghurt
for the croutons
½ tsp curry powder
30g olive oil
squeeze lemon juice
2 slices thick white bread

Melt butter in a saucepan, add onion, ginger, curry paste and cook until onions turn yellow, about 4 mins. Add parsnips and apple and stir over a medium heat to coat the vegetables. Add stock and bring to the boil then cover and simmer for 30 minutes. Puree in a blender or food processor then return to pan. Before serving, ladle a little soup into a bowl and whisk in the yoghurt, then combine with rest of soup. Add salt and pepper to taste.
Preheat oven to 200C/ 400F /Gas 6
Beat curry powder, olive oil and lemon juice together in a bowl. Remove crusts from bread and cut into cubes. Roll bread in mixture, place on a baking tray and bake until crisp and golden brown.