Preserved Dried Tomatoes

Begin by washing the tomatoes and removing the stalks, then slice them in half across the middle, turn the cut side down on a plate and squeeze out the seeds.

Lay some double layers of kitchen paper on a work surface and leave each half upside down on them to drain while you get on with preparing the rest. When they're all ready, turn them over and very lightly sprinkle the insides with salt – don't overdo this or you will lose the lovely concentrated sweetness when the tomatoes are dried. Now lay the tomatoes, cut side down, on the wire cooling trays, leaving just enough space between them so that they do not touch.

Next, lay some foil on the bottom shelf of the oven to catch any drips and save on oven cleaning, then place the two racks in the oven, leaving space for the air to circulate freely between the shelves. As you close the door, wedge it with a skewer (or something similar) to stop it closing completely – it needs only about ¼ inch (5 mm) gap, just sufficient to stop the build-up of heat so that the tomatoes dry rather than cook.

If the tomatoes are of medium size they will probably need 8 hours to dry completely, but take a look at them after 6 hours and remove any that appear to be ready. At this stage you can turn them the other way up. What you want are the tomatoes to be dried but still retaining a slight fleshy feel – don't let them go too papery. If in doubt, taste one: they should be chewy and the flavour a concentrated tomato sweetness.

Have ready the jar, clean and sterilised. When the tomatoes are cool, pack them into the jar – not too tightly – and top up with the oil before sealing and labelling. We have stored these for six months and they have kept beautifully.