Preheat the oven to 350°F. Fit a wire rack into a rimmed baking sheet. Slice each tomato lengthwise into 4 1/2-inch slices. Place on the wire rack.
In a small bowl, mix the garlic, thyme, and parsley; season with salt and pepper. Divide evenly among the tomato slices, spooning about 1/2 teaspoon on each. Drizzle the olive oil over the tomatoes. Roast until the herb mixture is lightly browned and the tomato skins are wrinkled, about 1 hour. Transfer the baking sheet to a wire rack to cool. Serve.