These oven-dried tomatoes are lovely but are really only worth making if you have a glut of tomatoes from your own plants (or someone else’s). Otherwise, they work out to be very expensive. It may be hard to be exact about the quantity you'll end up with after drying tomatoes, as it will depend on the size and juiciness of your tomatoes.
• 4-1/2 pounds tomatoes
• 4 teaspoons sea salt
• Freshly ground black pepper
• 4 teaspoons superfine sugar (caster sugar)
• 1 cup white balsamic vinegar or white wine vinegar
• 1/2 cup olive oil, or more if needed
Preheat the oven to 212 degrees Fahrenheit.
Halve the tomatoes and scoop out the seeds with a spoon. Put the halves, cut side up, on wire racks set in roasting pans (the tomatoes shouldn’t touch each other).
Sprinkle each with salt, pepper, and sugar. Leave for 15 minutes so the flavors can penetrate, and then turn them over.
Put the tomatoes in the oven. The length of time it will take to dry them will depend on the size and juiciness of the tomatoes, but take a look after 3-1/2 hours and see how they’re doing.
(I usually find that large plum tomatoes take more than 4 hours.) They should be shrunken but still plump and not brittle.
Carefully pull them off the rack (they'll stick; try not to tear them).
Leave tomatoes to cool a little, and then put them in a broad shallow bowl, pour over the vinegar, and leave them for 1 hour.
Put the tomatoes with the vinegar into a warm, dry, sterilized jar and pour in the olive oil; cover tomatoes completely.
Keep them in the refrigerator and eat within 4 weeks.