Tomatoes are generally rubbish through three quarters of the year in the non-Mediterranean part of Europe. Tasteless and watery, with thick skins and not much flavour. Vine-ripened, cherry, even organic are really not worth the bother or the price – it makes you long for the times when produce wasn’t available out of its season.
The thing to do to improve the flavour exponentially is to roast them for a long time at low temperature, in plenty of oil. Confit, in a word. You can confit not only duck legs as it happens but pretty much anything; and the purpose may be intensifying the flavour rather than the ultimate tenderisation like with meat.
Sliced or just halved, they will sit happily in a puddle of oil for a couple of hours until the skins become leathery and tinged with caramelisation around the edges. I like to eat them just like that, at room temperature, but you can do a very wonderful snack or appetizer by slapping a disc of all-butter puff pastry over the confit slices. Bake, stand and turn upside down onto a plate – the easiest tomato upside down tart.