If sun-drying tomatoes is not a viable option for you, you can do it either in an oven or in a food dehydrator. Actually, it looks like the dehydrator is the best option because it lets you dry tomatoes without burning them.
As you will see in this video, the process is easy. Chop tomatoes and spread the pieces on the food dehydrator’s tray. You can spray some olive oil and flavoring agent or herbs, etc., on the tomatoes. Switch on the dehydrator and leave it on for a few hours. The time and the power setting will depend on the quantity of the tomatoes, the size and power of the machine.
Keep checking after every few hours and adjust the power setting as needed.
Other option – Dry and preserve tomatoes
It is also possible to dry tomatoes using an electric oven, as you can see in this video. As a bonus, the linked video will also show how to preserve oven-dried tomatoes correctly.
If you already have an oven, then I would not suggest buying a food dehydrator just to dry tomatoes. But if you are drying foods in your kitchen frequently, then buying a food dehydrator may be a good investment.
Video credit: CaliforniaGardener YouTube channel.