Jerusalem Artichokes

My heavy London clay soil seems to be ideal for these Jerusalem artichokes. It's extremely muddy down on the allotment at the moment so they took quite a bit of scrubbing with the garden hose and a brush to get them clean.

They always seem to be a bit of a fiddle to prepare and cook. Today I roasted some in the oven but the skins were still thick and leathery. Steaming seems to be a better option but still a bit fiddly. Does anyone have any handy hints for preparing artichokes? Whatever it takes, I am a big fan and I adore them!