Place a sieve over a large bowl to catch juices and, using your hands, coarsely tear vine-ripened tomatoes into large pieces. Squash cherry tomatoes between your fingers and add to sieve. Scatter with 2 tsp sea salt and stand for 20 minutes, then pour juices into a small saucepan, add shallot and simmer over medium heat for 5 minutes or until reduced to 2 tbsp. Add sherry vinegar, olive oil and sugar and season to taste with sea salt and freshly ground black pepper.
Transfer tomatoes to a serving bowl or platter and drizzle with dressing. Thinly slice mature goat’s cheese, scatter over tomatoes and serve immediately.