Like Greyhound Mum my tart didn't set in the specified time so I put it in the oven for quite a while longer and by the time it cooled down in the fridge and it was just set, but because I cooked it longer, I thought the pastry was overdone. I wondered if it was because I used fresh cherries--only had 500g not 680 as specified in the book, but they were very plump and juicy and barely fit in the tart tin, and therefore could not fit the whole quantity of the filling in. Also the cherries were very sweet, so there wasn't the contrast of sweet and tart Cookie mentioned. Might try another time with Morello cherries, maybe.