This is one of the all-time great desserts. The secret for a luscious caramelised pear topping is in cooking the pears on top of the stove before baking the tart in the oven. It is a cousin of the famous apple upside-down Tarte Tatin.
1.75kg (4lb) firm but ripe pears such as Rocha, Williams or Packham
Quarter, peel and core the pears. Toss the pears in a bowl with a few tablespoons of the sugar as you work. Melt the butter and remaining sugar in a 24cm (9½-inch) ovenproof, cast-iron frying-pan (or you