ingredients 250g mascarpone 1 tbsp wasabi paste 1 finely chopped 10g tarragon, finely chopped 1 spring onion, finely sliced (20g) 2 banana shallots, thinly sliced widthways (100g) 2 tbsp pedro ximã©nez sherry vinegar (or another good-quality sweet sherry vinegar) 1 tbsp olive oilâ  1kg mixed tomatoes, cut i