The subject of sweet onions was much discussed at December's Secret Garden Club session on the allium family. I've long been fascinated by these ever since a trip to the US where I encountered the strong cult following enjoyed by that named varieties such as Walla Walla Sweets.
Walla Wallas hail from - oh yes - Walla Walla county in Washington State in the far northwest of the US. They look just like an ordinary yellow onion, but have been selectively cultivated since the beginning of the 20th century, when they were first brought to the US from Corsica, to maximise their sweetness.
I've always wanted to try growing some Walla Walla Sweets - or failing that, Vidalias from Georgia, or the Hawaiian Maui onion - but seeds are understandably hard to come by in London.
My Walla Wallas were sown on February 29th and are now germinating. So they are still very tiny and I'm still uncertain how they'll fare. In the meantime, I've been given a generous bagful of Oakley sweet onions by Pete Thompson of Brook Farm in Great Oakley in Essex. The Oakley onion is a strain of French onion from the Bourbonnais, and their delicate nature means that the mature bulbs are all harvested by hand.
According to Pete, they are 'just a bit sweeter than a Cox apple'. They would make for a pretty overpowering apple, I reckon. But that sweetness means that the onions caramelises beautifully when cooked, in a tart or in onion marmalade, for example. They also work well sliced finely into salads, where you get the onion bite without it being too heady, much like a spring onion, although I would say they are both sweeter and more pungent than a spring onion.