Arrange the tomato halves on the baking sheet in a single layer, cut-side facing up.
Drizzle evenly with extra virgin olive oil and sprinkle some sugar lightly over the tomato halves (add the optional balsamic vinegar and dried oregano if using). Season with salt and pepper.
Place in the preheated oven and bake the tomatoes until they are still juicy and slightly wrinkled – about 2-3 hours.
Transfer the tomatoes to a platter to let cool.
Garnish with chopped mint, basil or parsley.
Keep refrigerated in an airtight container for up to five days.