I say "preserve" somewhat tongue-in-cheek, as these tomatoes never last more than a couple of days at our house - they are just too delicious! In fact, roasting concentrates the natural sweetness of the tomatoes, so that they are almost like candy.
Here is my recipe. You can skip the sugar, if you want, and the tomatoes will still be sweet, but this way accentuates the sweet tomato flavor.
Tomates Confits / Sun Dried Tomatoes
Preheat oven to 150-200o (ie; your oven’s lowest setting). Line a baking sheet with aluminum foil, if you want to save on clean-up later.
Wash and quarter 3 lbs. of plum or Roma tomatoes. Leave the skins on, but remove most of the seeds and juice, leaving just the tomato flesh. Lay the tomato quarters on the baking sheet, skin side down, in a single layer. Sprinkle with:
1 T. white sugar
freshly ground sea salt & black pepper
1 T. chopped, fresh rosemary leaves
2 T. fresh thyme leaves
Lightly drizzle extra virgin olive oil over the tomatoes and put them in the oven for 1 hour. Turn tomatoes over (skin side up) and roast for another 2 hours. They will be withered and less moist, but not as dried out as sun dried tomatoes.
For SUN DRIED TOMATOES:
After following the above instructions, turn the oven off, but leave the tomatoes in the oven to dry out overnight (or an additional 12 hours).
Scrape the extra herbs and olive oil off the aluminum foil, and pour over the tomatoes. These can be stored in the refrigerator for a couple of weeks (if they don't get eaten immediately!) Alternatively, they can be place in jars, covered with extra virgin olive oil, and stored in a dark spot for several months.
· Whole garlic cloves and/or fresh pearl onions may be roasted in between the tomato slices. Simply peel them and sprinkle with the herbs and olive oil, along with the tomatoes.
· Other herbs may be used, such as tarragon, basil or savory. (If using basil, it must be well oiled, to prevent singeing.)