Fill a clean sink or other large vessel half full with water and add the tomatoes. Working with one tomato at a time, rinse then using a small sharp knife remove the core and the blossom-end scar.

On a cutting board cut the tomato in half across the equator for round tomatoes, or lengthwise for Roma-type tomatoes. Scrape the seed cavities with a finger (for Romas) or gently but firmly squeeze and shake the tomato (for other types) to remove the seeds and jelly.

Cut the tomato halves into smaller pieces, at least 1 by 1 inch, and place in a single layer on a paper plate. Repeat until the plate is full, then microwave on Medium (see note) for 2 to 2½ minutes or until hot.

Remove the plate from the microwave and dump the tomato pieces onto a dehydrator tray. Arrange the pieces skin-side down if possible (this helps reduce sticking). Sprinkle lightly with salt (and seasoning, if using). Repeat with as many tomatoes and dehydrator trays as you have.

Plug the dehydrator in and set the temperature to 135° F. If the dehydrator does not have a fan, rearrange the trays at least once every 8 to 10 hours to ensure even drying. If the dehydrator does have a fan, you can probably skip this step, but check your user manual to be sure.

Check on the tomatoes at least every 12 hours until they begin to shrivel and dry. Once they have reached your desired level of dryness, unplug the dehydrator and let stand at least 15 minutes. Remove the tomatoes from the trays and store in the freezer in freezer-safe packaging up to 1 year.

To rehydrate, for each half-cup of dried tomatoes add about a tablespoon of water. Shake to distribute the water, then simply let stand on the counter for about an hour, covered. Or microwave,  covered, about 30 seconds on High. Or refrigerate overnight. Use as you would use commercial sun-dried tomatoes.

Seven pounds of tomatoes yields about 1 cup of sun-dried tomatoes.