12 ripe medium tomatoes, cored and halved crosswise (about 3 pounds)
2 tablespoons extra-virgin olive oil
Salt and freshly ground pepper
1 head garlic, separated into cloves (about 15)
4 thyme sprigs
Preheat the oven to 350° and line a rimmed baking sheet with parchment paper. Arrange the tomatoes, cut side down, on the baking sheet and drizzle with the olive oil. Season with salt and pepper and scatter the garlic and thyme on top.
Roast the tomatoes for about 20 minutes, or until the skins begin to wrinkle. Remove the baking sheet from the oven and carefully pull off the tomato skins. Return the baking sheet to the oven and roast the tomatoes until leathery on the outside but still slightly wet on the underside, about 1 1/2 hours longer. Peel the garlic and discard the skins and the thyme.
The tomatoes and garlic can be refrigerated in a glass jar for up to 3 weeks.