Note that these tomatoes won’t be shelf stable – you’ll have to store them in the refrigerator or freezer. I like to freeze my cooled oven-dried tomatoes in a single layer on a sheet pan, then transfer them to a resealable bag, then store the bag in the freezer. That way, I can pull out as few or as many tomatoes as I want. (If you put them in a resealable bag before freezing them in a single layer, they’ll just freeze into one blob of tomatoes, making it hard to use them any way besides all at once.)
Freshly ground black pepper
Preheat the oven to 250°F. Arrange wire racks on top of rimed baking sheets
Meanwhile, halve your tomatoes (quarter the larger ones) and seed them. Arrange the tomatoes, cut side up, on the wire racks. (They can be close together, but they shouldn’t be touching. If you’re doing more than one variety of tomato, it’s best to put different varieties on different racks, because they might need different cooking times.) Drizzle the tomatoes with olive oil and sprinkle generously with salt and pepper.
Bake the tomatoes until they’re wrinkled and shrunken, 4 to 10 hours depending on the tomatoes’ size and water content and how wet or dry you want them to be. (I like to cook them until as much water as possible has cooked off, until it looks like, if I cook them any longer, they’ll brown and burn.) Cool thoroughly on the racks before refrigerating for several days or freezing for several months.