Preheat oven to 200°F. Line a rimmed baking sheet with aluminum foil, parchment paper or a silpat.

Warm cumin seeds in a small, dry skillet over medium heat. Cook until fragrant but not browned, shaking the skillet occasionally (about 3 minutes). Transfer seeds to the canister of a spice grinder or the bowl of a mortar and pestle. Let cool completely then grind into a fine powder.

Arrange tomatoes, cut side up, on the prepared baking sheet. Season the cut side with kosher salt and freshly ground black pepper. Drizzle each tomato with olive oil (they should be glistening with oil, not swimming in it). Finish with an even sprinkling of ground, toasted cumin (it may seem like a lot of cumin, but it works well in the end).

Bake for 11 - 14 hours, until the tomatoes have shriveled to 1/2 to 1/4 inch thickness. Cooking time will vary based on the size of your tomatoes. I checked mine around hour 10, then each hour afterwards. The batch pictured above was done at hour 12. The tomatoes will still be moist inside but have slightly crisp, brown edges.

Cool completely. Serve with toasted bread, cheese and fresh herbs. The tomatoes can also be enjoyed tossed with pasta or as a pizza topping.

To store, place the tomatoes in an airtight container and cover with extra-virgin olive oil. They will last for up to 2 weeks.