These tomatoes make wonderful additions to sandwiches and pasta sauces, or can be served on their own as a side dish with fish or chicken.
Heat oven to 250 degrees. Slice tomatoes thickly, to yield about three slices per tomato. Eat or discard the ends. Place slices on a parchment-covered baking sheet.
Mix together salt, pepper, and sugar. Brush tomatoes with olive oil, and sprinkle a large pinch of salt mixture on each tomato. Sprinkle on herbs, if using.
Roast the tomatoes for 3 hours. Or roast for 2 hours, turn off oven, and leave overnight.