Nigella's "Tomato, Mozzarella & Basil"

Ingredients

11 oz (1 dry pint) cherry or grape tomatoes, halved½ tsp dried oregano1 Tbsp olive oil salt and pepper, to taste1 cup basil leaves5 Tbsp extra virgin olive oil1 ½ tsp red wine vinegar8 oz fresh mozzarella, preferably buffalo

Directions

1. Preheat the oven to 425°F.
2. In a small roasting pan in which the tomatoes will fit snugly (I use a tarte Tatin pan) arrange the tomatoes cut-side up. Going over each tomato half, one by one, grind a little pepper and sprinkle on a little salt and the oregano, then dribble the tablespoon of olive oil over and transfer the pan to the oven to cook for 25 minutes, though check at 20 just in case they are softened and heat-wilted by then. Remove and let cool to room temperature or just above. (They can be left at room temperature for about 4 hours.)
3. To make the sauce, put the basil leaves and 2 tablespoons extra-virgin olive oil and 1 teaspoon vinegar and a small sprinkle of salt into a suitable bowl or cup, and blend to a deep-green purée with an immersion blender. Add another 1–2 tablespoons extra-virgin olive oil as needed to form a not-entirely-smooth brilliant green paste that can be poured; taste to see if you want the remaining 1⁄2 teaspoon vinegar or more salt, and blend in if you do.
4. Take the mozzarella out of any liquid, drain, tear into pieces, and, on a platter, arrange the mozzarella blossoms and the cooked, cooled tomato halves, then drizzle the basil dressing over them, and your beautiful creation is ready to be served, preferably with bread.