Finely chop an onion, a celery stalk & a large peeled tangy apple & add to a large pan with 30g butter. Cover & cook gently 15m.4
Add 2T chopped mint, increase heat & stir in 1T curry powder.
Cook 1m, stirring then remove pan from heat & blend in 2T flour.
Add 1.25L chicken or veg stock & add 1t salt, bring soup to boil.
Lower heat, partially cover & simmer 15m. Cool for 5m.
Whizz soup then return to pan, heat again before swirling through 1c natural yoghurt before serving.