Preheat the grill to high.

Cut the tomatoes in half and place on a baking tray cut-sides up.

Trickle the tomatoes with olive oil and season generously with salt and freshly ground black pepper.

Scatter over the thyme leaves and place under the grill until the skins have blackened a little.

Pour the grilled tomatoes and all their juices into a bowl.

Roughly crush the tomatoes using the back of a fork.

Stir in the torn basil leaves.

Add a little red wine vinegar for sharpness if the tomatoes are too sweet, or a little sugar if they are too sharp, to taste.

Finish the sauce by stirring in the olives.

Serve the cooked spaghetti topped with the sauce, tossing well to coat evenly.