Makes 4 cups of tomato halves.
5 lbs plum tomatoes, cut in half lengthwise
Kosher salt
Fresh black pepper
3 cloves garlic, minced (optional)
Olive oil (not extra virgin)
Preheat oven to 200°F. Line a rimmed sheet pan with several layers of aluminum foil.
Set the tomatoes cut side up on the baking sheet. Sprinkle them lightly with kosher salt and fresh black pepper. If you're using garlic sprinkle the minced garlic over all the tomatoes (I opted not to use garlic, to give me more flexibility in how I use the finished tomatoes).
Drizzle olive oil liberally over all of the tomatoes.
Bake at 200F for 8 hours.
At that point, check the tomatoes to make sure they are not too crispy; this will depend on the size of your tomatoes. The goal is to have tomatoes that are chewy and still slightly moist, though totally collapsed. If you are using large tomatoes, you might want to cook them for one additional hour. However, the green tomatoes have less moisture than red ones, so although red plum tomatoes might cook for 10 hours, the green ones will be finished in 8-9 hours.
Remove from the oven and let cool completely. Pack into containers or jars for the refrigerator, or into ziploc bags for the freezer. Be sure to include the oil from the pan, too; it has wonderful flavor.
Slow-roasted tomatoes will keep in the refrigerator for 2-3 weeks, or in the freezer for a year or more.