Begin the pastry 4 hours in advance so it has time to rest. Place the flour, lard, butter, icing sugar and salt into a food processor and pulse until it resembles breadcrumbs

Pour in the egg and milk and pulse again until a dough forms. Tip out onto the surface and bring together into a ball, but don't over work the dough. Wrap in cling film and leave to rest in the fridge for 2 hours

Once the pastry has rested, roll it out until 2mm thick and, using a 9-10cm round cutter, cut out 6 circles. Line the tarts then leave in the fridge to rest for a further 2 hours

Preheat an oven to 165°C/gas mark 3. Line the rested pastry cases with greaseproof paper and fill with baking beans or dry rice. Blind-bake for 15 minutes, then remove the paper and baking beans and leave to cool

While the pastry cooks and cools, prepare the filling. Cut 18 small florets from the cauliflower and place in a pan with 100g of the butter. Place a lid on and leave gently steam and caramelise for 30 minutes

Finely dice the rest of the cauliflower and place in a pan with the remaining 100g of butter. Sweat until soft, then add the double cream and bring to the boil

Transfer the cream mixture to a blender and blitz to a smooth purée. Taste and season with salt, then pass through a fine sieve and keep warm

To make the Gruyère sabayon, set up a heatproof bowl over a pan of simmering water. Add the egg yolks and whisk continuously, ensuring they remain at a low temperature and do not scramble

Once thickened and warm, add the cheese bit by bit until emulsified into the yolks. Then add the milk and a pinch of cayenne and salt to taste

Once the sabayon has completely warmed through, transfer to an Isi cream whipper and charge with 2 canisters. Keep the whipper in a bowl of warm water to keep warm

To cook the cauliflower fungus, melt the butter in a frying pan and gently cook the fungus with a pinch of salt

To assemble, spoon the purée into the tartlet cases and arrange the cauliflower florets and mushrooms in a circle around the edge of each tartlet. Finish with the sabayon in the centre and decorate with the cresses and flowers