Heat your oven to 125 F/ 150C. Wash and slice your tomatoes in half. (Cherry tomatoes or other smallish varieties work best)
Lay your tomatoes out on a baking tray or two, cut side up. Season well and sprinkle over your herbs de Provence o alternative. Drizzle lightly with olive oil (they don’t want to be swimming in it).
Roast in the oven for at least 3 hours, or longer if you think they need a bit more. But don’t let them shrivel up too much, you want some juiciness to remain.
You can either place them into sterilised jars and cover completely with olive oil to preserve them. This is great in small jars and best if you want to use them fairly quickly once opened. They will mould if they do not remain completely covered in oil once opened.
Or just place a portion of your choice for a single use into individual freezer bags and freeze. Defrost as required. They retain all their flavour and punch this way also.