Good King Henry 

Good King Henry (Chenopodium bonus-henricus), sometimes known as mercury, is a perennial that grows to around 30-60cm (1-2ft) high.

The leaves can be cooked as, and taste like, spinach and they can also be eaten raw in salads. Even the young shoots are very good, tied together in bundles and cooked and eaten like asparagus. The flower buds can be sautéed in butter.

Being hardy, it will provide pickings through the winter if covered with a cloche or similar protection.