Dry Roma tomatoes by removing the stem and stem base, cutting the tomato in half, and removing the moisture by applying heat or exposing it to sunlight. You can dry tomatoes in an oven or a dehydrator,or by air-drying them in direct sunlight.
People often oil tomatoes with olive oil and season them with salt, thyme, oregano, basil or other herbs before drying them. To sun-dry the tomatoes, put them outside on a hot, dry day. Leave them in a container that allows for excellent airflow to carry the moisture away, but that also prevents bugs or debris from coming into contact them. Tight knit netting and cheesecloth are two good options for protecting the tomatoes. The tomatoes must be left out in hot, dry conditions for up to three days to achieve a satisfactory level of dehydration.