Preheat oven to 300 F/ 150Line a baking sheet with parchment paper.

Cut the tomatoes in half lengthwise and place pulp side up on a baking sheet.

Nestle the unpeeled garlic cloves between the tomatoes in various places in the pan. Sprinkle the tomatoes with salt and sugar. Spritz with the balsamic. Bake at low temperature for about 1 ½ hours, or until the tomatoes are shrivelled, caramelized, a little leathery on the bottom, but still a bit plump. Remove and cool. Squeeze out the pulp from the roasted garlic.

Place the tomatoes inside a clean glass jar, sprinkling in a little of the oregano and strewing the roasted garlic between layers as you go, and gently pressing down with the back of a spoon to get them all in. They should fit inside a 750 ml jar. Pour in enough olive oil to cover the tomatoes completely. Store in the fridge indefinitely.

The tomatoes are great tossed with pasta, over salads, as a snack on their own and even added to a piping hot baked potato with a little sea salt, extra virgin Greek olive oil, and a dollop of either Greek yogurt or crumbled feta.