Start with your best ripe tomatoes. Depending on the size of your fruit, halve or quarter them, or cut them into thick slices and wedges (about 1/2 to 3/4 inch) if they’re especially large. Cherry and grape tomatoes can be oven-dried whole.
Arrange your tomatoes on large baking sheets, skin sides down and barely touching. If you have oven-safe cooling racks, you can place them over the baking sheet firsts for maximum air flow around the tomatoes, which will speed up the drying process.
Quick tip: Place tomatoes of similar thicknesses together on the same baking sheet. They’ll generally dry at the same rate, so they’ll be easier to pick off and pull out of the oven.
Sprinkle the tomatoes sparingly with salt—I like to use flaky sea salt or Himalayan pink salt. Remember that your tomatoes will lose around 90 to 95 percent of their moisture in the oven, so any salt you use will become concentrated in what’s left of the tomatoes.
Add your favorite herbs right on top—I used a few sprigs of fresh oregano, winter savory, and lemon thyme on mine, but you can also try rosemary, basil, marjoram, chives, or whatever you have on hand.