Thanks to their creamy texture, ripe pears make a particularly plush sorbet. Adding a little brandy to the pear puree keeps the sorbet from freezing hard. For maximum effect, top each serving with a splash of Champagne at the dinner table.

Peel the pears with a vegetable peeler. Quarter the pears lengthwise, core, and cut into large chunks. Put the chunks in a large saucepan with the water. Bring to a simmer over moderate heat, then cover, adjust the heat to maintain a gentle simmer, and cook until the pears are tender, about 10 minutes.

Transfer the pears to a food processor and puree until completely smooth. Measure the volume, then return the puree to the food processor. Add sugar in the ratio of 1½ cups sugar to 4 cups puree. Add the lemon juice and brandy and puree until the mixture is completely smooth and the sugar has dissolved. Transfer to a bowl, cover, and refrigerate until thoroughly chilled.

Freeze the chilled puree in an ice-cream maker according to the manufacturer's directions. Because of the alcohol, the sorbet will not freeze hard. Transfer the sorbet to a freezer container and freeze for at least 30 minutes to allow it to firm up before serving.

Scoop the sorbet into martini glasses or parfait glasses. Top each portion with 1 ounce (2 tablespoons) of Champagne. Serve immediately.