Score a cross in the base of each tomato. Put in a heatproof bowl and cover with boiling water. Leave for 30 seconds, then transfer to cold water and peel the skin away from the cross. Cut each tomato in half, scoop out the seeds and finely chop the flesh. Lay the eggplant on a tray, sprinkle with salt and leave for 30 minutes. Rinse under water and pat dry