In Italy, this preparation is best done at the end of July or on the first 20 days of August, when the sun is very hot, so the tomatoes will be very dry and perfectly ripe.
ripe, firm, medium-size tomatoes
extra-virgin olive oil
How to make Sun-dried Tomatoes:
Clean the tomatoes with a wet towel, cut them in half length-wise, remove the seeds, put them over a grate with the open side up, and sprinkle liberally with salt (if they are not salted enough, they will become moldy).
Leave them in the sun for 4-5 days, turning occasionally, and taking them indoors at night. At the end of each day, drain the water they will have oozed. On the last day, wash the basil leaves and let them dry over a cloth in the shade. Put the tomatoes halves back together, placing a basil leaf in the middle of the cut, and press well. Then place them in layers in a clean, dry jar. Press well, add some peperoncino and clove garlic if you wish, cover the tomatoes entirely with oil, close the pot with an airtight cover and store it. They will be ready for consumption in 2 weeks.
Tomatoes prepared like this can be served as part of an antipasto or as a side dish for boiled and broiled meats. If you cannot dry the tomatoes outside because of the weather, you can dry them in a warm oven (pre-heated and then turned off).
Regional Recipe from Sicily