Preheat oven to 200 °. Wash tomatoes and remove the tops. Cut them in half, lengthwise. Pour olive oil in bowl and, using a pastry brush, lightly coat the tomatoes. Put the tomatoes on a baking tray or dish, skin side down. Sprinkle with sea salt, or herb/spice of choice. Following Molly’s direction, I use about a pinch of salt per four tomato halves. Bake the tomatoes for six hours. Allow tomatoes to cool to room temperature before storing in an airtight container. Kept this way, they will keep for several days. But good luck keeping your fingers out of them.