Wash the tomatoes, pat dry and cut in half depending on the size. Then place in a baking dish or on a baking sheet and season with olive oil, sugar, balsamic vinegar, sea salt and pepper.
Rinse off the rosemary, strip off the needles and finely chop, then pour over the tomatoes.
Preheat the oven to 200 ° C top / bottom heat (convection: 180 ° C) and roast the tomatoes in it for about 20-25 minutes.