1. Wash the thyme sprigs and pat them dry on a cloth.
2. Make the shortcrust pastry and allow it to rest in the fridge for at least 30 minutes.
3. Lightly grease four 3½ inch (10cm) loose-bottomed individual tart cases.
4. Roll out the pastry and line each tart case.
5. Place the cases onto a baking tray.
6. Finely dice the shallots.
7. Drizzle a little olive oil into a small frying pan.
8. Heat gently, add the shallots and sweat without color for about 5 minutes.
9. Remove from the pan and drain on kitchen paper to remove any excess oil.
10. Blanch the tomatoes, skin and finely slice.
11. Mix the cream and mustard in a bowl and add the shallots.
12. Strip 8 of the thyme sprigs from their stalks and add to the bowl. Mix well.
13. Pre-heat the oven to 190°C (Gas Mark 5).
14. Spoon the cream and mustard mixture into the tart cases and spread evenly.
15. Neatly arrange the sliced tomatoes on top of each tart case.
16. Season with a little sea salt and black pepper.
17. Place in the pre-heated oven and bake for around 30 minutes.
18. Remove the tomato tarts from the oven and allow to cool slightly.
19. Carefully remove the tart cases.
20. Sprinkle a little caster sugar over each tomato tart and heat the grill to very hot.
21. Place the tomato tarts under the grill for a few moments to caramelize the sugar alternately use a blow torch, to give them a quick blast.
22. Serve the tomato tarts warm on a warmed plate.
23. Drizzle a little olive oil over each tomato tart and plate and garnish with the remaining thyme springs and any remaining baby tomatoes.
24. Add a light dusting of freshly milled black pepper over the plate.