Slice your tomatoes (take the seeds out if you want…I don’t and they are still fine) and lay them on a baking sheet lined with parchment paper.
Place them in a 200 degree oven for several hours to dry out. Mine took 7 hours. It all depends on the moisture content of your tomatoes. If you seed them and take out the excess moisture, they will dry faster. I like to leave the juices in the tomatoes because they will concentrate and taste better.
When they are completely dry, place in a zip lock bag and place in the freezer. Add these tomatoes to your soups, sauces, stews or lasagna. Will store up to a year!