Tip the quinoa and celery into a pan and cover with plenty of water. Bring to the boil, then reduce the heat and simmer for 10 mins. Add the soya beans, bring back to the boil and cook for 7 mins more. Drain well, tip into a bowl and set aside.

Add the oil, vinegar and spring onions, and leave to cool slightly before stirring in the parsley and mint. Serve two portions topped with half the segmented oranges and half the feta crumbled over. Chill the remaining salad for another day, then segment the remaining oranges and crumble over the feta just before serving. Will keep chilled in an airtight container for up to three days.