Score one end of each tomato and drop them into the boiling salty water until the skin starts to peel off (about 20 seconds). Then shock them in a bath of ice water. With a small knife peel off the skin (it should come off quite easily). Slice the tomatoes lengthwise and remove the seeds with a spoon. Lay the tomatoes face down on a baking tray covered with parchment paper. Sprinkle salt and cracked pepper and remember to season every tomato. Roughly chop the rosemary and thyme and sprinkle over tomatoes. Sweeten the tomatoes with a light dusting of confectioners' sugar (sprinkling through a wire strainer will help an even dusting with no clumping!). Drizzle olive oil over top, again making sure to get some on every tomato.
Preheat the oven to 250 degrees F. Put the pan in the oven and cook for about 8 hours.
Cook overnight as they must cook for 8 hours.