Preheat the oven to 110ºC/225ºF. Wash and halve a punnet or two of cherry tomatoes and lay them on a baking parchment-lined baking sheet, cut side up. Season each with sea salt, one or two thyme leaves and drizzle with light olive oil. Cook for about 2 hours, depending on size. Try one: they should have shrunk to half the size and taste intense. Place into sterilised jars and cover with sunflower oil. Keep in the fridge and eat within one month