Core and halve the plum tomatoes lengthwise.

Dehydrate tomatoes using a dehydrator or a 225F oven until they reach the texture of dried apricots.

This could take up to a day or longer.

Boil red wine vinegar in a nonreactive saucepan.

Blanch the dehydrated tomatoes in the boiling vinegar for 1 minute, then drain well.

Layer tomatoes in sterilized jars.

Add half the basil, capers, peppercorns, and salt to each jar.

Slowly pour extra virgin olive oil into the jars, ensuring tomatoes are submerged.

Cap the jars tightly and let them sit in a cool place overnight.

Check oil level the next day and add more if needed.

Repeat the check a few more times to make sure tomatoes are covered.

Recap and store in a cool place for 6 weeks.

Refrigerate after opening and serve at room temperature.