Leaves - raw or cooked. A spinach substitute, the shoot tips are harvested when about 8cm long, this encourages plenty of side growth with lots more shoots to harvest. A delicious substitute for spinach, the very young leaves and shoots can also be eaten raw in salads. The young leaves are best, older leaves developing an acrid taste Source: https://pfaf.org/
New Zealand spinach
Find more about this plant on Wikipedia.