Tomato and basil tarts

Years ago, when I was a moody teenager rather than a sulky adult, my mum used to take me to a snazzy restaurant called the Caprice. I always ordered the same things, the tuna with lentils and the tomato tart. I have since become friends with Mark Hix, who used to be the head chef there, and he has generously given me this recipe so that you may enjoy it.