Mix the flour, water, oil and salt in a food processor. Add the oil little by little.
Wrap the pastry dough in cling film and leave to rest for at least 30 minutes. Grease your tart tin with olive oil.
Rinse the hijiki seaweed well and soak in plenty of water to rehydrate. Cut the vegetables (carrot, lotus root, mushrooms, leek) into about 1 cm cubes. Preheat the oven to 180℃.
Blitz the crushed kudzu, white miso and tofu in a food processor until creamy.
Stir-fry the vegetables with olive oil. Salt and pepper.
Sandwich the pastry dough with 2 pieces of cling film. Roll out the dough with a rolling pin into a circle larger than your tart tin circumference and a thickness of 2-3 mm.
Peel off the upper sheet of cling film and flip over onto the tart tin, so that the dough lands inside with the cling film side up.
Prick the base of the pastry to let the steam escape. Put stir-fried vegetables from Step 5 and pour in the cream from Step 4.
Bake in the oven preheated to 180°C for about 40 minutes.