Heat oven to 250°F. Line a large baking sheet with parchment paper.
Slice the tomatoes in half lengthwise. Place them cut-side-up on the baking sheet.
Bake for 2.5 to 3.5 hours, or until the tomatoes are dried out, keeping an eye on the tomatoes so that they don’t burn.
Remove from the oven. Serve immediately. Or to store, transfer the sun-dried tomatoes to a jar and fill with olive oil until the tomatoes are completely covered. Add in any desired seasonings (such as a clove of garlic and/or herbs), then cover and refrigerate for up to 2 weeks.
Wash tomatoes and remove stems. Slice the tomatoes in half.
Arrange the tomatoes on your dehydrator trays. Leave space around each tomato, so they dry faster. Dry until they feel leathery and dry to the touch.
Store in an air-tight container. Shake the container every day for the first week, so the remaining moisture is evenly distributed throughout the tomatoes. This is an important step that will prevent them from molding.