Drying fruits and vegetables has been done for a long time as a way to preserve them for future use. It can be time consuming and requires a lot of space when using the sun, the modern way is using commercial dehydrators to remove moisture. For the home cook a oven will work just fine.
I like drying tomatoes and use meaty Roma's or use the sweet cherry varieties, these have good flavor to begin with and just get more intense and concentrated as they dry. Big tomatoes need to be cut in half to help release moisture where cherry tomatoes can be left whole, I lightly season them with kosher salt and pepper, extra virgin olive oil, chopped garlic and maybe rosemary or thyme. Place on parchment paper or a nonstick sheet pan in a oven set very low (100F/37C) If your oven is lit with a pilot light then that might just be enough heat to slowly dry them. It can be left in the oven overnight or longer depending on how dry you want them to be. They should then be stored refrigerated packed in olive oil until ready for use. Simple and sweet with intense tomato flavor!