To my onions-fried in butter, I added two sticks of celery, two apples (just the eatable part), a carton of passatta and a pouch of bought chicken stock.  Also, pepper and herbes de Provence.  Once this was cooked, and left ‘to cool down a little’,  I got distracted and forgot about it, but John kindly blended it for me.

The celery fills the soup out; perhaps it would be better with less celery and more apples, but it is a delicious soup, even so.