Perfect for summer lunches or an al fresco dinner party, this informal dish is simple to make and very healthy. Serve with slices of toasted ciabatta.
3½ portions vegetables
The tuna can be left in its marinade for several hours or overnight in the refrigerator, along with the crumb topping and the basil-filled tomatoes. To make the crumbs, whizz day-old bread briefly in a food processor until crumbs form.