Whole roast mackerel, leeks, kohlrabi and jerusalem artichokes

Peel and roughly chop 250g of the artichokes (leaving aside the other 50g for crisps). Put them in a bowl of cold water with the juice of half the lemon to stop them browning.

Melt the butter in a frying pan and fry the garlic and shallots until soft. Drain the artichokes, add to the pan and fry for a few minutes, then add a splash of water and cook for 15-20 minutes until very tender. Tip everything into a bowl and blitz with a hand blender (or in a liquidiser) to make a purée, seasoning well.

For the crisps, heat a pan of oil ⅓ full to 160C, or until a cube of bread browns in 45 seconds. Peel and slice the artichokes on a mandoline, or with a very sharp knife, as thin as you would like them.

Peel the kohlrabi then shave into strips on a mandoline or with a vegetable peeler as thinly as possible. Put in a bowl and mix with olive oil, sherry vinegar and a pinch of salt. Heat a griddle pan to hot, grill the leeks until very tender, then add to the kohlrabi bowl.

Heat the oven to 200C/fan 180C/gas 6. Flatten out the mackerel by pushing down on the backbone so they butterfly out. Put skin-side up on a tray, then season with salt and pepper and roast for around 12-15 minutes. A good way to check and see if the flesh is cooked is to push the meat near the head – if it’s flaky and moves when you touch it it’s ready. Squeeze the other half of the lemon over the mackerel when they come out of the oven.

To serve, spoon the purée on to the plate then put the whole mackerel on top. Spoon the kohlrabi and leeks over the top of the fish scattering the artichoke crisps all over. Add a cheek or wedge of lemon to each plate.