COOK

1. Combine all the ingredients in a medium saucepan, and bring to a boil over medium-high heat, stirring to dissolve the sugar. Continue cooking for 5 to 8 minutes, until the pears are soft. Remove from the heat and let cool slightly.

CHILL

1. Puree the pear mixture in 2 batches in a food processor until completely smooth. Force through a sieve.
2. Fill a large bowl with ice and water. Pour the mixture into a 1-gallon Ziploc freezer bag and submerge the sealed bag in the ice bath. Let stand, adding more ice as necessary, until cold, about 30 minutes.

FREEZE

1. Pour the sorbet base into the frozen canister and spin just until the consistency of very softly whipped cream.
2. Pack the sorbet into a storage container, press a sheet of parchment directly against the surface, and seal with an airtight lid. Freeze in the coldest part of your freezer until firm, at least 4 hours.