1. For the pickled carrots, heat the vinegar, 190ml water and honey in a pan until simmering. Cool for 10 minutes, then pour over the carrots, refrigerate for 2 hours.
2. Place the flour, Parmigiano Reggiano and butter in a food processor, and pulse until it turns to a breadcrumb consistency. Then add the yolk, milk and tarragon, and process until it turns into dough. Refrigerate for 1 hour.
3. Preheat the oven to 180°C, gas mark 4. Roll out the dough to 3mm thick and refrigerate for 10 minutes. Cut 6 x 10cm rounds and prick with a fork. Place on 2 baking trays lined with baking parchment and bake for 15 minutes. Allow to cool on the tray for 2 minutes.
4. For the roasted carrots, toss together the carrots, oil, sugar and salt and pepper. Arrange on a large baking tray lined with baking parchment and roast in the preheated oven for 30 minutes.
5. For the onion jam, heat the oil in a large pan over a medium heat, add the onions and cook, stirring occasionally, for 12-15 minutes or until caramelised.
6. Stir in the vinegar with the sugar and salt. Cover and turn the heat to low and cook for a further 15 minutes, stirring occasionally. Season with black pepper. Allow the mixture to cool.
7. Using a vegetable peeler, shave the cooled pickled carrots, leaving some of the green stalks on the carrots for colour.
8. To assemble and serve, generously spread each of the cooled pastry bases with about 25g goat’s cheese. Spoon a little onion jam into the centre, then top with 3-4 of the caramelised oven-roasted carrots, served with shavings of pickled carrot salad on the side. Finish with a scattering of small Greek basil leaves and sea salt flakes.