Heat oven to 140C/fan 120C/gas 1. Halve the tomatoes and put on baking sheets, cut sides up. Brush each lightly with a little olive oil and sprinkle with salt and pepper. Sprinkle the oregano over the tomatoes. Cook for 2-3 hrs until semi-dried. Leave to cool, then pack into a plastic container and chill for up to 24 hrs.
When ready to serve, scatter the rocket over a platter and arrange the tomatoes on top. Drizzle with a little olive oil
and balsamic vinegar, then scatter over the pine nuts.