Cardoons are popular in Italy and France but unfortunately not so much in the UK. The inner stalks and roots are very pleasant served like asparagus and also make excellent fritters.
Trim the cardoons, rub with a little of the lemon juice and cut into 10cm (4in) lengths. Bring a large pan of water to the boil, add the juice of 1 lemon and some salt, then add the cardoons and cook for 15-20 minutes, until just tender. Remove and drain well.
Mix together the onion, garlic, vegetable oil and remaining lemon juice, add the hot cardoons and leave to marinate for 1 hour. Then remove from the marinade and dry thoroughly on kitchen paper.
To prepare the batter, sift the flour and salt into a bowl and add the lemon zest. Make a well in the centre, add the eggs and beat until blended. Add the oil, lemon juice and beer, whisk well together, then cover and leave to rest for 1 hour at room temperature. Meanwhile, mix together the aioli, Parmesan and capers.
Heat some oil for